The following `tip` changes can be tested by building VictoriaLogs from the latest commit of [VictoriaMetrics](https://github.com/VictoriaMetrics/VictoriaMetrics/) repository
* FEATURE: [`join` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#join-pipe): add an ability to add prefix to all the log field names from the joined query, by using `| join by (<by_fields>) (<query>) prefix "some_prefix"` syntax.
* FEATURE: [`_time` filter](https://docs.victoriametrics.com/victorialogs/logsql/#time-filter): allow specifying offset without time range. For example, `_time:offset 1d` matches all the logs until `now-1d` in the [`_time` field](https://docs.victoriametrics.com/victorialogs/keyconcepts/#time-field). This is useful when building graphs for time ranges with some offset in the past.
* FEATURE: [`/select/logsql/tail` HTTP endpoint](): support for `offset` query arg, which can be used for delayed emission of matching logs during live tailing. Thanks to @Fusl for the initial idea and implementation in [this pull request](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/7428).
* FEATURE: [vlogscli](https://docs.victoriametrics.com/victorialogs/querying/vlogscli/): allow enabling and disabling wrapping of long lines, which do not fit screen width, with `\wrap_long_lines` command.
* FEATURE: [syslog data ingestion](https://docs.victoriametrics.com/victorialogs/data-ingestion/syslog/): allow overriding default [stream fields](https://docs.victoriametrics.com/victorialogs/keyconcepts/#stream-fields) with the given [log fields](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model) during data ingestion. See [these docs](https://docs.victoriametrics.com/victorialogs/data-ingestion/syslog/#stream-fields). See [this feature request](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/7480).
* FEATURE: [syslog data ingestion](https://docs.victoriametrics.com/victorialogs/data-ingestion/syslog/): allow dropping the specified [log fields](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model) during data ingestion. See [these docs](https://docs.victoriametrics.com/victorialogs/data-ingestion/syslog/#dropping-fields).
* FEATURE: [syslog data ingestion](https://docs.victoriametrics.com/victorialogs/data-ingestion/syslog/): allow adding the specified [log fields](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model) during data ingestion. See [these docs](https://docs.victoriametrics.com/victorialogs/data-ingestion/syslog/#adding-extra-fields). See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/7354).
* FEATURE: [Loki data ingestion](https://docs.victoriametrics.com/victorialogs/data-ingestion/#loki-json-api): show the original request body on parse errors. This should simplify debugging. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/7490).
* BUGFIX: [`values` stats function](https://docs.victoriametrics.com/victorialogs/logsql/#values-stats): fix a bug, which could lead to corrupted results. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/7458).
* BUGFIX: [`uniq_values`](https://docs.victoriametrics.com/victorialogs/logsql/#uniq_values-stats), [`min`](https://docs.victoriametrics.com/victorialogs/logsql/#min-stats), [`max`](https://docs.victoriametrics.com/victorialogs/logsql/#max-stats), [`row_min`](https://docs.victoriametrics.com/victorialogs/logsql/#row_min-stats) and [`row_max`](https://docs.victoriametrics.com/victorialogs/logsql/#row_max-stats) stats functions: fix a bug, which could return non-matching field values for these functions. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/7458).
* BUGFIX: [HTTP querying APIs](https://docs.victoriametrics.com/victorialogs/querying/#http-api): properly take into account the `end` query arg when calculating time range for [`_time:duration` filter](https://docs.victoriametrics.com/victorialogs/logsql/#time-filter). Previously the `_time:duration` filter was treated as `_time:[now-duration, now)`, while it should be treated as `_time:[end-duration, end)`.
* FEATURE: support [structured metadata](https://grafana.com/docs/loki/latest/get-started/labels/structured-metadata/) when ingesting logs with [Grafana Loki ingestion protocol](https://docs.victoriametrics.com/victorialogs/data-ingestion/promtail/). See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/7431).
* FEATURE: support returning historical logs from [live tailing API](https://docs.victoriametrics.com/victorialogs/querying/#live-tailing) via `start_offset` query arg. For example, request to `/select/logsql/tail?query=*&start_offset=5m` returns logs for the last 5 minutes before starting returning live tailing logs for the given `query`.
* FEATURE: add an ability to specify extra fields for logs ingested via [HTTP-based data ingestion protocols](https://docs.victoriametrics.com/victorialogs/data-ingestion/#http-apis). See `extra_fields` query arg and `VL-Extra-Fields` HTTP header in [these docs](https://docs.victoriametrics.com/victorialogs/data-ingestion/#http-parameters).
* FEATURE: add [`block_stats` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#block_stats-pipe) for returning various per-block stats. This pipe is useful for debugging.
* FEATURE: [web UI](https://docs.victoriametrics.com/victorialogs/querying/#web-ui): add sorting of logs by groups and within each group by time in desc order. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/7184) and [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/7045).
* BUGFIX: properly sort fields with floating-point numbers by [`sort` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#sort-pipe). Previously floating-point numbers could be improperly sorted because they were treated as strings, and [natural sorting](https://en.wikipedia.org/wiki/Natural_sort_order) was incorrectly applied to them. For example, `0.123` was treated as bigger than `0.9`.
* FEATURE: add support for extra filters across all the [HTTP querying APIs](https://docs.victoriametrics.com/victorialogs/querying/#http-api). See [these docs](https://docs.victoriametrics.com/victorialogs/querying/#extra-filters) for details. This is needed for implementing quick filtering on field values at [this feature request](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/7365).
* BUGFIX: properly apply [`replace`](https://docs.victoriametrics.com/victorialogs/logsql/#replace-pipe) and [`replace_regexp`](https://docs.victoriametrics.com/victorialogs/logsql/#replace_regexp-pipe) pipes to identical values in adjacent log entries. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/7162).
* FEATURE: allow specifying a list of log fields, which may contain log message, via `_msg_field` query arg and via `VL-Msg-Field` HTTP request header. For example, `_msg_field=message,event.message` instructs obtaining [message field](https://docs.victoriametrics.com/victorialogs/keyconcepts/#message-field) from the first non-empty field out of the `message` and `event.message` fields. See [these docs](https://docs.victoriametrics.com/victorialogs/data-ingestion/#http-parameters) for details.
* FEATURE: accept logs without [`_msg` field](https://docs.victoriametrics.com/victorialogs/keyconcepts/#message-field). In this case the `_msg` field is automatically set to the value specified in the `-defaultMsgValue` command-line flag.
* BUGFIX: fix `runtime error: index out of range [0] with length 0` panic during low-rate data ingestion. The panic has been introduced in [v0.38.0](https://github.com/VictoriaMetrics/VictoriaMetrics/releases/tag/v0.38.0-victorialogs). See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/7391).
* FEATURE: added the ability to receive systemd (journald) logs over network. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4618).
* FEATURE: improve performance for queries over large volume of logs with big number of [fields](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model) (aka `wide events`).
* FEATURE: improve performance for [`/select/logsql/field_values` HTTP endpoint](https://docs.victoriametrics.com/victorialogs/querying/#querying-field-values).
* FEATURE: improve performance for [`field_values` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#field_values-pipe) when it is applied directly to [log filter](https://docs.victoriametrics.com/victorialogs/logsql/#filters).
* FEATURE: add an ability to return `rank` field from [`top` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#top-pipe). For example, the following query returns `1..5` rank per each returned `ip` with the biggest number of logs over the last 5 minute: `_time:5m | top 5 by (ip) rank`.
* BUGFIX: [web UI](https://docs.victoriametrics.com/victorialogs/querying/#web-ui): fix various glitches with updating query responses. The issue was introduced in [v0.36.0](https://github.com/VictoriaMetrics/VictoriaMetrics/releases/tag/v0.36.0-victorialogs). See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/7279).
* FEATURE: add basic [alerting rules](https://github.com/VictoriaMetrics/VictoriaMetrics/blob/master/deployment/docker/rules/alerts-vlogs.yml) for VictoriaLogs process. See details at [monitoring docs](https://docs.victoriametrics.com/victorialogs/#monitoring).
* FEATURE: improve [`stats` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#stats-pipe) performance on systems with many CPU cores when `by(...)` fields contain big number of unique values. For example, `_time:1d | stats by (user_id) count() x` should be executed much faster when `user_id` field contains millions of unique values.
* FEATURE: improve performance for [`top`](https://docs.victoriametrics.com/victorialogs/logsql/#top-pipe), [`uniq`](https://docs.victoriametrics.com/victorialogs/logsql/#uniq-pipe) and [`field_values`](https://docs.victoriametrics.com/victorialogs/logsql/#field_values-pipe) pipes on systems with many CPU cores when it is applied to [log fields](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model) with big number of unique values. For example, `_time:1d | top 5 (user_id)` should be executed much faster when `user_id` field contains millions of unique values.
* FEATURE: improve performance for [`field_names` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#field_names-pipe) when it is applied to logs with hundreds of [log fields](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model).
* FEATURE: optimize [LogsQL queries](https://docs.victoriametrics.com/victorialogs/logsql/), which need to scan big number of logs with big number of [log fields](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model) (aka `wide events`). The performance for such queries is improved by 10x and more depending on the number of log fields in the scanned logs. The performance improvement is visible when querying logs ingested after the upgrade to this release.
* FEATURE: skip empty log fields in query results, since they are treated as non-existing fields in [VictoriaLogs data model](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model). This should reduce the level of confusion for end users when they see empty log fields.
* FEATURE: allow using [`format` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#format-pipe) for creating output labels from existing log fields at [`/select/logsql/stats_query`](https://docs.victoriametrics.com/victorialogs/querying/#querying-log-stats) and [`/select/logsql/stats_query_range`](https://docs.victoriametrics.com/victorialogs/querying/#querying-log-range-stats) endpoints.
* FEATURE: [web UI](https://docs.victoriametrics.com/victorialogs/querying/#web-ui): add the ability to cancel running queries. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/7097).
* BUGFIX: avoid panic at `lib/logstorage.(*blockResultColumn).forEachDictValue()` when the query contains [stats with additional filters](https://docs.victoriametrics.com/victorialogs/logsql/#stats-with-additional-filters). The panic has been introduced in [v0.33.0](https://github.com/VictoriaMetrics/VictoriaMetrics/releases/tag/v0.33.0-victorialogs) in [this commit](https://github.com/VictoriaMetrics/VictoriaMetrics/commit/a350be48b68330ee1a487e1fb09b002d3be45163).
* BUGFIX: [vmui](https://docs.victoriametrics.com/#vmui): fix error messages rendering from overflowing the screen with long messages. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/7207).
* FEATURE: [vlogscli](https://docs.victoriametrics.com/victorialogs/querying/vlogscli/): add ability to live tail query results - see [these docs](https://docs.victoriametrics.com/victorialogs/querying/vlogscli/#live-tailing).
* FEATURE: [vlogscli](https://docs.victoriametrics.com/victorialogs/querying/vlogscli/): add compact output mode for query results. It can be enabled by typing `\c` and then pressing `enter`. See [these docs](https://docs.victoriametrics.com/victorialogs/querying/vlogscli/#output-modes).
* FEATURE: [vlogscli](https://docs.victoriametrics.com/victorialogs/querying/vlogscli/): add `-accountID` and `-projectID` command-line flags for setting `AccountID` and `ProjectID` values when querying the specific [tenants](https://docs.victoriametrics.com/victorialogs/#multitenancy).
* FEATURE: [vlogscli](https://docs.victoriametrics.com/victorialogs/querying/vlogscli/): add ability to display results in `logfmt` mode, single-line and multi-line JSON modes according [these docs](https://docs.victoriametrics.com/victorialogs/querying/vlogscli/#output-modes).
* FEATURE: [vlogscli](https://docs.victoriametrics.com/victorialogs/querying/vlogscli/): preserve `less` output after the exit from scrolling mode. This should help re-using previous query results in subsequent queries.
* FEATURE: add [`len` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#len-pipe) for calculating the length for the given [log field](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model) value in bytes.
* BUGFIX: [`count_uniq` stats function](https://docs.victoriametrics.com/victorialogs/logsql/#count_uniq-stats): do not count field values, which aren't matched by the used filters. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/7152).
* BUGFIX: do not return field values with zero matching logs from [`field_values`](https://docs.victoriametrics.com/victorialogs/logsql/#field_values-pipe), [`top`](https://docs.victoriametrics.com/victorialogs/logsql/#top-pipe) and [`uniq`](https://docs.victoriametrics.com/victorialogs/logsql/#uniq-pipe) pipes. See [this issue](https://github.com/VictoriaMetrics/victorialogs-datasource/issues/72#issuecomment-2352078483).
* FEATURE: [data ingestion](https://docs.victoriametrics.com/victorialogs/data-ingestion/): accept Unix timestamps in seconds in the ingested logs. This simplifies integration with systems, which prefer Unix timestamps over text-based representation of time.
* FEATURE: [`sort` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#sort-pipe): allow using `order` alias instead of `sort`. For example, `_time:5s | order by (_time)` query works the same as `_time:5s | sort by (_time)`. This simplifies the to [LogsQL](https://docs.victoriametrics.com/victorialogs/logsql/) transition from SQL-like query languages.
* FEATURE: [`stats` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#stats-pipe): allow using multiple identical [stats functions](https://docs.victoriametrics.com/victorialogs/logsql/#stats-pipe-functions) with distinct [filters](https://docs.victoriametrics.com/victorialogs/logsql/#stats-with-additional-filters) and automatically generated result names. For example, `_time:5m | count(), count() if (error)` query works as expected now, e.g. it returns two results over the last 5 minutes: the total number of logs and the number of logs with `error` [word](https://docs.victoriametrics.com/victorialogs/logsql/#word). Previously this query couldn't be executed because the `if (...)` condition wasn't included in the automatically generate result name, so both results had the same name - `count(*)`.
* BUGFIX: properly calculate [`uniq`](https://docs.victoriametrics.com/victorialogs/logsql/#uniq-pipe) and [`top`](https://docs.victoriametrics.com/victorialogs/logsql/#top-pipe) pipes. Previously they could return invalid results in some cases.
* FEATURE: [web UI](https://docs.victoriametrics.com/victorialogs/querying/#web-ui): improved readability of staircase graphs and tooltip usability. See [this comment](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6545#issuecomment-2336805237).
* FEATURE: [web UI](https://docs.victoriametrics.com/victorialogs/querying/#web-ui): simplify query input by adding only the label name when `ctrl`+clicking the line legend. See [this comment](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6545#issuecomment-2336805237).
* FEATURE: [web UI](https://docs.victoriametrics.com/victorialogs/querying/#web-ui): keep selected columns in table view on page reloads. Before, selected columns were reset on each update. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/7016).
* FEATURE: allow skipping `_stream:` prefix in [stream filters](https://docs.victoriametrics.com/victorialogs/logsql/#stream-filter). This simplifies writing queries with stream filters. Now `{foo="bar"}` is the recommended format for stream filters over the `_stream:{foo="bar"}` format.
* FEATURE: allow using `-` instead of `!` as `NOT` operator shorthand in [logical filters](https://docs.victoriametrics.com/victorialogs/logsql/#logical-filter). For example, `-info -warn` query is equivalent to `!info !warn`. This simplifies transition from other query languages with full-text search support, which usually use `-` as `NOT` operator.
* BUGFIX: consistently return matching log streams sorted by time from [`stream_context` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#stream_context-pipe). Previously log streams could be returned in arbitrary order with every request. This could complicate using `stream_context` pipe.
* BUGFIX: [`stream_context` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#stream_context-pipe): add missing `_msg="---"` delimiter between stream contexts belonging to different [log streams](https://docs.victoriametrics.com/victorialogs/keyconcepts/#stream-fields). This should simplify investigating `stream_context` output for multiple matching log streams.
* FEATURE: [web UI](https://docs.victoriametrics.com/victorialogs/querying/#web-ui): add button for enabling auto refresh, similarly to VictoriaMetrics vmui. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/7017).
* FEATURE: drop logs without [`_msg`](https://docs.victoriametrics.com/victorialogs/keyconcepts/#message-field) field or with empty `_msg` field, since this field is required to be non-empty in [VictoriaLogs data model](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model). See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6785).
* FEATURE: improve performance of analytical queries, which do not need reading the `_time` field. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/7070).
* FEATURE: add [`blocks_count` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#blocks_count-pipe), which can be used for counting the number of matching blocks for the given query. For example, `_time:5m | blocks_count` returns the number of blocks with logs for the last 5 minutes. This pipe can be useful for debugging purposes.
* FEATURE: support [ingesting logs](https://docs.victoriametrics.com/victorialogs/data-ingestion/) with `_time` field, which doesn't contain timezone information. For example, `2024-09-20T10:20:30`. In this case the local timezone of the host where VictoriaLogs runs is used. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6721).
* FEATURE: reduce memory usage when [`stream_context` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#stream_context-pipe) is applied to [log streams](https://docs.victoriametrics.com/victorialogs/keyconcepts/#stream-fields) with big number of messages. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6730).
* BUGFIX: fix Windows build, which has been broken in [v0.29.0](https://github.com/VictoriaMetrics/VictoriaMetrics/releases/tag/v0.29.0-victorialogs). See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6973).
* BUGFIX: properly return logs from [`/select/logsql/tail` endpoint](https://docs.victoriametrics.com/victorialogs/querying/#live-tailing) if the query contains [`_time:some_duration` filter](https://docs.victoriametrics.com/victorialogs/logsql/#time-filter) like `_time:5m`. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/7028). The bug has been introduced in [v0.29.0](https://github.com/VictoriaMetrics/VictoriaMetrics/releases/tag/v0.29.0-victorialogs).
* BUGFIX: properly return logs without [`_msg`](https://docs.victoriametrics.com/victorialogs/keyconcepts/#message-field) field when `*` query is passed to [`/select/logsql/query` endpoint](https://docs.victoriametrics.com/victorialogs/querying/#querying-logs) together with positive `limit` arg. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6785). Thanks to @jiekun for identifying the root cause of the issue.
* BUGFIX: support [ingesting logs](https://docs.victoriametrics.com/victorialogs/data-ingestion/) with `_time` field containing whitespace delimiter between the date and time instead of `T` delimiter. For example, `2024-09-20 10:20:30`. This is valid [ISO8601 format](https://en.wikipedia.org/wiki/ISO_8601) aka `SQL datetime` format, which sometimes is used in production. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6721).
* BUGFIX: return all the requested surrounding logs for [`stream_context` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#stream_context-pipe). Previously only logs matching the [`_time` filter](https://docs.victoriametrics.com/victorialogs/logsql/#time-filter) were returned. This is needed for [this feature](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/7063).
* FEATURE: add [`/select/logsql/stats_query` HTTP API](https://docs.victoriametrics.com/victorialogs/querying/#querying-log-stats), which is going to be used by [vmalert](https://docs.victoriametrics.com/vmalert/) for executing alerting and recording rules against VictoriaLogs. See [this feature request](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6942) for details.
* FEATURE: add [`/select/logsql/stats_query_range` HTTP API](https://docs.victoriametrics.com/victorialogs/querying/#querying-log-range-stats), which is going to be used by [VictoriaLogs plugin for Grafana](https://docs.victoriametrics.com/victorialogs/victorialogs-datasource/) for building time series panels. See [this feature request](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6943) for details.
* FEATURE: optimize [multi-exact queries](https://docs.victoriametrics.com/victorialogs/logsql/#multi-exact-filter) with many phrases to search. For example, `ip:in(path:="/foo/bar" | keep ip)` when there are many unique values for `ip` field among log entries with `/foo/bar` path.
* FEATURE: [web UI](https://docs.victoriametrics.com/victorialogs/querying/#web-ui): add support for displaying the top 5 log streams in the hits graph. The remaining log streams are grouped into an "other" label. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6545).
* FEATURE: [web UI](https://docs.victoriametrics.com/victorialogs/querying/#web-ui): add the ability to customize the graph display with options for bar, line, stepped line, and points.
* FEATURE: [web UI](https://docs.victoriametrics.com/victorialogs/querying/#web-ui): add fields for setting AccountID and ProjectID. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6631).
* FEATURE: [web UI](https://docs.victoriametrics.com/victorialogs/querying/#web-ui): add a toggle button to the "Group" tab that allows users to expand or collapse all groups at once.
* FEATURE: [web UI](https://docs.victoriametrics.com/victorialogs/querying/#web-ui): introduce the ability to select a key for grouping logs within the "Group" tab.
* FEATURE: [web UI](https://docs.victoriametrics.com/victorialogs/querying/#web-ui): display the number of entries within each log group.
* FEATURE: [web UI](https://docs.victoriametrics.com/victorialogs/querying/#web-ui): move the Markdown toggle to the general settings panel in the upper left corner.
* FEATURE: [web UI](https://docs.victoriametrics.com/victorialogs/querying/#web-ui): add search functionality to the column display settings in the table. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6668).
* FEATURE: [web UI](https://docs.victoriametrics.com/victorialogs/querying/#web-ui): add the ability to select all columns in the column display settings of the table. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6668). Thanks to @yincongcyincong for the [pull request](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/6680).
* FEATURE: Allow to define ingestion parameters via headers. Supported headers - `VL-Msg-Field`,`VL-Stream-Fields`,`VL-Ignore-Fields`,`VL-Time-Field`, `VL-Debug`. See this [PR](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/6443) for details.
* FEATURE: [vlinsert](https://docs.victoriametrics.com/victorialogs/): added OpenTelemetry logs ingestion support. See this [PR](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/6218) for details.
* BUGFIX: properly handle Logstash requests for Elasticsearch configuration when using `outputs.elasticsearch` in Logstash pipelines. Previously, the requests could be rejected with `400 Bad Request` response. Updates [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4750).
* BUGFIX: [vmui](https://docs.victoriametrics.com/#vmui): fix `not found index.js` error when loading vmui in VictoriaLogs. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6764). Thanks to @yincongcyincong for the [pull request](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/6770).
* BUGFIX: properly execute queries with `OR` [filters](https://docs.victoriametrics.com/victorialogs/logsql/#logical-filter) for distinct [log fields](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model). For example, `field1:foo OR field2:bar`. Previously logs matching these filters may be skipped during querying. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6554) for details. Thanks to @yincongcyincong for the [pull request](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/6556).
* FEATURE: [web UI](https://docs.victoriametrics.com/victorialogs/querying/#web-ui): show a spinner on top of bar chart until user's request is finished. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6558).
* FEATURE: [web UI](https://docs.victoriametrics.com/victorialogs/querying/#web-ui): use compact representation of JSON lines at `JSON` tab if only a single [log field](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model) is queried. See [this feature request](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6559).
* FEATURE: [web UI](https://docs.victoriametrics.com/victorialogs/querying/#web-ui): properly show the number of matching logs on the selected time range at bar chart for queries with arbitrary [pipes](https://docs.victoriametrics.com/victorialogs/logsql/#pipes), including [`stats` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#stats-pipe) and [`top` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#top-pipe).
* BUGFIX: properly JSON-encode strings with special chars in [HTTP querying API](https://docs.victoriametrics.com/victorialogs/querying/#http-api) responses. This fixes the `error decode response: invalid character 'x' in string escape code` error in [VictoriaLogs datasource for Grafana](https://github.com/VictoriaMetrics/victorialogs-datasource/). See [this issue](https://github.com/VictoriaMetrics/victorialogs-datasource/issues/24). The issue has been introduced in the release [v0.9.0](https://github.com/VictoriaMetrics/VictoriaMetrics/releases/tag/v0.9.0-victorialogs).
* FEATURE: add `-syslog.useLocalTimestamp.tcp` and `-syslog.useLocalTimestamp.udp` command-line flags, which could be used for using the local timestamp as [`_time` field](https://docs.victoriametrics.com/victorialogs/keyconcepts/#time-field) for the logs ingested via the corresponding `-syslog.listenAddr.tcp` / `-syslog.listenAddr.udp`. By default the timestamp from the syslog message is used as [`_time` field](https://docs.victoriametrics.com/victorialogs/keyconcepts/#time-field). See [these docs](https://docs.victoriametrics.com/victorialogs/data-ingestion/syslog/).
* BUGFIX: make slowly ingested logs visible for search as soon as they are ingested into VictoriaLogs. Previously slowly ingested logs could remain invisible for search for long time.
* BUGFIX: return the proper surrounding logs for [`stream_context` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#stream_context-pipe) when additional [pipes](https://docs.victoriametrics.com/victorialogs/logsql/#pipes) are put after the `stream_context` pipe. This has been broken in [v0.26.0](https://github.com/VictoriaMetrics/VictoriaMetrics/releases/tag/v0.26.0-victorialogs).
* FEATURE: add ability to return log position (aka rank) after sorting logs with [`sort` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#sort-pipe). This can be done by adding `rank as <fieldName>` to the end of `| sort ...` pipe. For example, `_time:5m | sort by (_time) rank as position` instructs storing position of every sorted log line into `position` [field name](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model).
* FEATURE: add delimiter log with `---` message between log chunks returned by [`stream_context` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#stream_context-pipe). This should simplify investigation of the returned logs.
* FEATURE: reduce memory usage when big number of context logs are requested from [`stream_context` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#stream_context-pipe).
* FEATURE: add ability to select surrounding logs in front and after the selected logs via [`stream_context` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#stream_context-pipe). This functionality may be useful for investigating stacktraces, panics or some correlated log messages. This functionality is similar to `grep -A` and `grep -B`.
* FEATURE: add ability to return top `N``"fields"` groups from [`/select/logsql/hits` HTTP endpoint](https://docs.victoriametrics.com/victorialogs/querying/#querying-hits-stats), by specifying `fields_limit=N` query arg. This query arg is going to be used in [this feature request](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6545).
* BUGFIX: fix `runtime error: index out of range [0] with length 0` panic when empty lines are ingested via [Syslog format](https://docs.victoriametrics.com/victorialogs/data-ingestion/syslog/) by Cisco controllers. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6548).
* FEATURE: add `/select/logsql/tail` HTTP endpoint, which can be used for live tailing of [LogsQL query](https://docs.victoriametrics.com/victorialogs/logsql/) results. See [these docs](https://docs.victoriametrics.com/victorialogs/querying/#live-tailing) for details.
* FEATURE: add `/select/logsql/stream_ids` HTTP endpoint, which can be used for returning [`_stream_id` values](https://docs.victoriametrics.com/victorialogs/keyconcepts/#stream-fields) with the number of hits for the given [LogsQL query](https://docs.victoriametrics.com/victorialogs/logsql/). See [these docs](https://docs.victoriametrics.com/victorialogs/querying/#querying-stream_ids) for details.
* FEATURE: add `-retention.maxDiskSpaceUsageBytes` command-line flag, which allows limiting disk space usage for [VictoriaLogs data](https://docs.victoriametrics.com/victorialogs/#storage) by automatic dropping the oldest per-day partitions if the storage disk space usage becomes bigger than the `-retention.maxDiskSpaceUsageBytes`. See [these docs](https://docs.victoriametrics.com/victorialogs/#retention-by-disk-space-usage).
* BUGFIX: properly take into account query timeout specified via `-search.maxQueryDuration` command-line flag and/or via `timeout` query arg. Previously these timeouts could be ignored during query execution.
* BUGFIX: [web UI](https://docs.victoriametrics.com/victorialogs/querying/#web-ui): fix the update of the relative time range when `Execute Query` is clicked. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6345).
* FEATURE: [syslog data ingestion](https://docs.victoriametrics.com/victorialogs/data-ingestion/syslog/): parse [STRUCTURED-DATA](https://datatracker.ietf.org/doc/html/rfc5424#section-6.3) into `SD-ID.field1=value1`, `SD-ID.field2=value2`, ..., `SD-ID.fieldN=valueN` [log fields](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model). Previously the `STRUCTURED-DATA` was parsed into a single log field with the `SD-ID` name and `field1=value1 field2=value2 ... fieldN=valueN` value. This could complicate querying of such data.
* BUGFIX: properly parse timestamps with timezones during [data ingestion](https://docs.victoriametrics.com/victorialogs/data-ingestion/) and [querying](https://docs.victoriametrics.com/victorialogs/querying/). This has been broken in [v0.20.0](https://github.com/VictoriaMetrics/VictoriaMetrics/releases/tag/v0.20.0-victorialogs). See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6508).
* FEATURE: allow specifying multiple `_stream_id` values in [`_stream_id` filter](https://docs.victoriametrics.com/victorialogs/logsql/#_stream_id-filter) via `_stream_id:in(id1, ..., idN)` syntax.
* FEATURE: allow specifying subquery for searching for `_stream_id` values inside [`_stream_id` filter](https://docs.victoriametrics.com/victorialogs/logsql/#_stream_id-filter). For example, `_stream_id:in(_time:5m error | fields _stream_id)` returns logs for [logs streams](https://docs.victoriametrics.com/victorialogs/keyconcepts/#stream-fields) with the `error` word across logs for the last 5 minutes.
* FEATURE: [web UI](https://docs.victoriametrics.com/victorialogs/querying/#web-ui): add a bar chart displaying the number of log entries over a time range. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6404).
* FEATURE: expose `_stream_id` field, which uniquely identifies [log streams](https://docs.victoriametrics.com/victorialogs/keyconcepts/#stream-fields). This field can be used for quick obtaining of all the logs belonging to a particular stream via [`_stream_id` filter](https://docs.victoriametrics.com/victorialogs/logsql/#_stream_id-filter).
* BUGFIX: properly parse timestamps with nanosecond precision for logs ingested via [jsonline format](https://docs.victoriametrics.com/victorialogs/data-ingestion/#json-stream-api). The bug has been introduced in [v0.20.0 release](https://github.com/VictoriaMetrics/VictoriaMetrics/releases/tag/v0.20.0-victorialogs).
* FEATURE: allow configuring multiple receivers with distinct configs for syslog messages. See [these docs](https://docs.victoriametrics.com/victorialogs/data-ingestion/syslog/#multiple-configs).
* BUGFIX: properly read syslog messages over TCP and TLS connections according to [RFC5425](https://datatracker.ietf.org/doc/html/rfc5425) when [data ingestion for syslog protocol](https://docs.victoriametrics.com/victorialogs/data-ingestion/syslog/) is enabled.
* FEATURE: add ability to accept logs in [Syslog format](https://en.wikipedia.org/wiki/Syslog). See [these docs](https://docs.victoriametrics.com/victorialogs/data-ingestion/syslog/).
* FEATURE: add ability to specify timezone offset when parsing [rfc3164](https://datatracker.ietf.org/doc/html/rfc3164) syslog messages with [`unpack_syslog` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#unpack_syslog-pipe).
* FEATURE: add [`top` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#top-pipe) for returning top N sets of the given fields with the maximum number of matching log entries.
* FEATURE: do not allow starting the [filter](https://docs.victoriametrics.com/victorialogs/logsql/#filters) with [pipe names](https://docs.victoriametrics.com/victorialogs/logsql/#pipes) and [stats function names](https://docs.victoriametrics.com/victorialogs/logsql/#stats-pipe-functions). This prevents from unexpected results returned by incorrect queries, which miss mandatory [filter](https://docs.victoriametrics.com/victorialogs/logsql/#query-syntax).
* FEATURE: treat unexpected syslog message as [RFC3164](https://datatracker.ietf.org/doc/html/rfc3164) containing only the `message` field when using [`unpack_syslog` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#unpack_syslog-pipe).
* FEATURE: allow using `where` prefix instead of `filter` prefix in [`filter` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#filter-pipe).
* FEATURE: disallow unescaped `!` char in [LogsQL](https://docs.victoriametrics.com/victorialogs/logsql/) queries, since it permits writing incorrect query, which may look like correct one. For example, `foo!:bar` instead of `foo:!bar`.
* FEATURE: [web UI](https://docs.victoriametrics.com/victorialogs/querying/#web-ui): add markdown support to the `Group` view. See [this pull request](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/6292).
* BUGFIX: return back the improved performance for queries with `*` filters (aka `SELECT *`). This has been broken in [v0.16.0](https://github.com/VictoriaMetrics/VictoriaMetrics/releases/tag/v0.16.0-victorialogs).
* FEATURE: [web UI](https://docs.victoriametrics.com/victorialogs/querying/#web-ui): improve displaying of logs. See [this pull request](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/6419) and the following issues: [6408](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6408), [6405](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6405), [6406](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6406) and [6407](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6407).
* FEATURE: add support for [day range filter](https://docs.victoriametrics.com/victorialogs/logsql/#day-range-filter) and [week range filter](https://docs.victoriametrics.com/victorialogs/logsql/#week-range-filter). These filters allow selecting logs on a particular time range per every day or on a particular day of the week.
* FEATURE: allow using `eval` instead of `math` keyword in [`math` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#math-pipe).
* FEATURE: add [`pack_logfmt` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#pack_logfmt-pipe) for formatting [log fields](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model) into [logfmt](https://brandur.org/logfmt) messages.
* FEATURE: allow using IPv4 addresses in [range comparison filters](https://docs.victoriametrics.com/victorialogs/logsql/#range-comparison-filter). For example, `ip:>'12.34.56.78'` is valid filter now.
* FEATURE: add `ceil()` and `floor()` functions to [`math` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#math-pipe).
* FEATURE: add support for bitwise `and`, `or` and `xor` operations at [`math` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#math-pipe).
* FEATURE: add support for automatic conversion of [RFC3339 time](https://www.rfc-editor.org/rfc/rfc3339) and IPv4 addresses into numeric representation at [`math` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#math-pipe).
* FEATURE: add ability to format numeric fields into string representation of time, duration and IPv4 with [`format` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#format-pipe).
* FEATURE: set `format` field to `rfc3164` or `rfc5424` depending on the [Syslog format](https://en.wikipedia.org/wiki/Syslog) parsed via [`unpack_syslog` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#unpack_syslog-pipe).
* BUGFIX: always respect the limit set in [`limit` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#limit-pipe). Previously the limit could be exceeded in some cases.
* FEATURE: add [`unpack_syslog` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#unpack_syslog-pipe) for unpacking [syslog](https://en.wikipedia.org/wiki/Syslog) messages from [log fields](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model).
* FEATURE: parse timestamps in [`_time` filter](https://docs.victoriametrics.com/victorialogs/logsql/#time-filter) with nanosecond precision.
* FEATURE: return the last `N` matching logs from [`/select/logsql/query` HTTP API](https://docs.victoriametrics.com/victorialogs/querying/#querying-logs) with the maximum timestamps if `limit=N` query arg is passed to it. Previously a random subset of matching logs could be returned, which could complicate investigation of the returned logs.
* FEATURE: add [`drop_empty_fields` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#drop_empty_fields-pipe) for dropping [log fields](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model) with empty values.
* FEATURE: add [`row_any`](https://docs.victoriametrics.com/victorialogs/logsql/#row_any-stats) function for [`stats` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#stats-pipe). This function returns a sample log entry per every calculated [group of results](https://docs.victoriametrics.com/victorialogs/logsql/#stats-by-fields).
* FEATURE: add `default` operator to [`math` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#math-pipe). It allows overriding `NaN` results with the given default value.
* FEATURE: add `exp()` and `ln()` functions to [`math` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#math-pipe).
* FEATURE: allow omitting result name in [`math` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#math-pipe) expressions. In this case the result name is automatically set to string representation of the corresponding math expression. For example, `_time:5m | math duration / 1000` is equivalent to `_time:5m | math (duration / 1000) as "duration / 1000"`.
* FEATURE: allow omitting result name in [`stats` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#stats-pipe). In this case the result name is automatically set to string representation of the corresponding [stats function expression](https://docs.victoriametrics.com/victorialogs/logsql/#stats-pipe-functions). For example, `_time:5m | count(*)` is valid [LogsQL query](https://docs.victoriametrics.com/victorialogs/logsql/) now. It is equivalent to `_time:5m | stats count(*) as "count(*)"`.
* BUGFIX: properly calculate the number of matching rows in `* | field_values x | stats count() rows` and in `* | unroll (x) | stats count() rows` queries.
* FEATURE: allow specifying fields, which must be packed into JSON in [`pack_json` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#pack_json-pipe) via `pack_json fields (field1, ..., fieldN)` syntax.
* BUGFIX: properly apply `if (...)` filters to calculated results in [`stats` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#stats-pipe) when [grouping by fields](https://docs.victoriametrics.com/victorialogs/logsql/#stats-by-fields) is enabled. For example, `_time:5m | stats by (host) count() logs, count() if (error) errors` now properly calculates per-`host` `errors`.
* FEATURE: add [`extract_regexp` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#extract_regexp-pipe) for extracting arbitrary substrings from [log fields](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model) with [RE2 regular expressions](https://github.com/google/re2/wiki/Syntax).
* FEATURE: add [`math` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#math-pipe) for mathematical calculations over [log fields](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model).
* FEATURE: add [`field_values` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#field_values-pipe), which returns unique values for the given [log field](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model).
* FEATURE: allow omitting `stats` prefix in [`stats` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#stats-pipe). For example, `_time:5m | count() rows` is a valid query now. It is equivalent to `_time:5m | stats count() as rows`.
* FEATURE: allow omitting `filter` prefix in [`filter` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#filter-pipe) if the filter doesn't clash with [pipe names](#https://docs.victoriametrics.com/victorialogs/logsql/#pipes). For example, `_time:5m | stats by (host) count() rows | rows:>1000` is a valid query now. It is equivalent to `_time:5m | stats by (host) count() rows | filter rows:>1000`.
* FEATURE: allow [`head` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#limit-pipe) without number. For example, `error | head`. In this case 10 first values are returned as `head` Unix command does by default.
* FEATURE: allow using [comparison filters](https://docs.victoriametrics.com/victorialogs/logsql/#range-comparison-filter) with strings. For example, `some_text_field:>="foo"` matches [log entries](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model) with `some_text_field` field values bigger or equal to `foo`.
* BUGFIX: properly apply [`in(...)` filter](https://docs.victoriametrics.com/victorialogs/logsql/#multi-exact-filter) inside `if (...)` conditions at various [pipes](https://docs.victoriametrics.com/victorialogs/logsql/#pipes). This bug has been introduced in [v0.12.0](https://github.com/VictoriaMetrics/VictoriaMetrics/releases/tag/v0.12.0-victorialogs).
* FEATURE: add [`pack_json` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#pack_json-pipe), which packs all the [log fields](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model) into a JSON object and stores it into the given field.
* FEATURE: add [`unroll` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#unroll-pipe), which can be used for unrolling JSON arrays stored in [log fields](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model).
* FEATURE: add [`replace_regexp` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#replace_regexp-pipe), which allows updating [log fields](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model) with regular expressions.
* FEATURE: improve performance for [`format`](https://docs.victoriametrics.com/victorialogs/logsql/#format-pipe) and [`extract`](https://docs.victoriametrics.com/victorialogs/logsql/#extract-pipe) pipes.
* FEATURE: improve performance for [`/select/logsql/field_names` HTTP API](https://docs.victoriametrics.com/victorialogs/querying/#querying-field-names).
* BUGFIX: prevent from panic in [`sort` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#sort-pipe) when VictoriaLogs runs on a system with one CPU core.
* BUGFIX: do not return referenced fields if they weren't present in the original logs. For example, `_time:5m | format if (non_existing_field:"") "abc"` could return empty `non_exiting_field`, while it shouldn't be returned because it is missing in the original logs.
* BUGFIX: properly initialize values for [`in(...)` filter](https://docs.victoriametrics.com/victorialogs/logsql/#multi-exact-filter) inside [`filter` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#filter-pipe) if the `in(...)` contains other [filters](https://docs.victoriametrics.com/victorialogs/logsql/#filters). For example, `_time:5m | filter ip:in(user_type:admin | fields ip)` now works correctly.
* FEATURE: add [`replace` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#replace-pipe), which allows replacing substrings in [log fields](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model).
* FEATURE: support [comparing](https://docs.victoriametrics.com/victorialogs/logsql/#range-filter) log field values with [special numeric values](https://docs.victoriametrics.com/victorialogs/logsql/#numeric-values). For example, `duration:>1.5s` and `response_size:<15KiB` are valid filters now.
* FEATURE: properly sort [durations](https://docs.victoriametrics.com/victorialogs/logsql/#duration-values) and [short numeric values](https://docs.victoriametrics.com/victorialogs/logsql/#short-numeric-values) in [`sort` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#sort-pipe). For example, `10s` goes in front of `1h`, while `10KB` goes in front of `1GB`.
* FEATURE: add an ability to preserve the original non-empty field values when executing [`extract`](https://docs.victoriametrics.com/victorialogs/logsql/#extract-pipe), [`unpack_json`](https://docs.victoriametrics.com/victorialogs/logsql/#unpack_json-pipe), [`unpack_logfmt`](https://docs.victoriametrics.com/victorialogs/logsql/#unpack_logfmt-pipe) and [`format`](https://docs.victoriametrics.com/victorialogs/logsql/#format-pipe) pipes.
* FEATURE: add an ability to preserve the original field values if the corresponding unpacked values are empty when executing [`extract`](https://docs.victoriametrics.com/victorialogs/logsql/#extract-pipe), [`unpack_json`](https://docs.victoriametrics.com/victorialogs/logsql/#unpack_json-pipe), [`unpack_logfmt`](https://docs.victoriametrics.com/victorialogs/logsql/#unpack_logfmt-pipe) and [`format`](https://docs.victoriametrics.com/victorialogs/logsql/#format-pipe) pipes.
* FEATURE: return the number of matching log entries per returned value in [HTTP API](https://docs.victoriametrics.com/victorialogs/querying/#http-api) results. This simplifies detecting [field](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model) / [stream](https://docs.victoriametrics.com/victorialogs/keyconcepts/#stream-fields) values with the biggest number of logs for the given [LogsQL query](https://docs.victoriametrics.com/victorialogs/logsql/).
* FEATURE: improve performance for [regexp filter](https://docs.victoriametrics.com/victorialogs/logsql/#regexp-filter) in the following cases:
* FEATURE: allow disabling automatic unquoting of the matched placeholders in [`extract` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#extract-pipe). See [these docs](https://docs.victoriametrics.com/victorialogs/logsql/#format-for-extract-pipe-pattern).
* BUGFIX: properly parse `!` in front of [exact filter](https://docs.victoriametrics.com/victorialogs/logsql/#exact-filter), [exact-prefix filter](https://docs.victoriametrics.com/victorialogs/logsql/#exact-prefix-filter) and [regexp filter](https://docs.victoriametrics.com/victorialogs/logsql/#regexp-filter). For example, `!~"some regexp"` is properly parsed as `not ="some regexp"`. Previously it was incorrectly parsed as `'~="some regexp"'` [phrase filter](https://docs.victoriametrics.com/victorialogs/logsql/#phrase-filter).
* BUGFIX: properly sort results by [`_time` field](https://docs.victoriametrics.com/victorialogs/keyconcepts/#time-field) when [`limit` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#limit-pipe) is applied. For example, `_time:5m | sort by (_time) desc | limit 10` properly works now.
* BUGFIX: [web UI](https://docs.victoriametrics.com/victorialogs/querying/#web-ui): fix loading web UI, which has been broken in [v0.9.0](https://github.com/VictoriaMetrics/VictoriaMetrics/releases/tag/v0.9.0-victorialogs).
* FEATURE: allow using `~"some_regexp"` [regexp filter](https://docs.victoriametrics.com/victorialogs/logsql/#regexp-filter) instead of `re("some_regexp")`.
* FEATURE: allow using `="some phrase"` [exact filter](https://docs.victoriametrics.com/victorialogs/logsql/#exact-filter) instead of `exact("some phrase")`.
* FEATURE: allow using `="some prefix"*` [exact prefix filter](https://docs.victoriametrics.com/victorialogs/logsql/#exact-prefix-filter) instead of `exact("some prefix"*)`.
* FEATURE: add ability to generate output fields according to the provided format string. See [these docs](https://docs.victoriametrics.com/victorialogs/logsql/#format-pipe).
* FEATURE: add ability to extract fields with [`extract` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#extract-pipe) only if the given condition is met. See [these docs](https://docs.victoriametrics.com/victorialogs/logsql/#conditional-extract).
* FEATURE: add ability to unpack JSON fields with [`unpack_json` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#unpack_json-pipe) only if the given condition is met. See [these docs](https://docs.victoriametrics.com/victorialogs/logsql/#conditional-unpack_json).
* FEATURE: add ability to unpack [logfmt](https://brandur.org/logfmt) fields with [`unpack_logfmt` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#unpack_logfmt-pipe) only if the given condition is met. See [these docs](https://docs.victoriametrics.com/victorialogs/logsql/#conditional-unpack_logfmt).
* FEATURE: add [`row_min`](https://docs.victoriametrics.com/victorialogs/logsql/#row_min-stats) and [`row_max`](https://docs.victoriametrics.com/victorialogs/logsql/#row_max-stats) functions for [`stats` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#stats-pipe), which allow returning all the [log fields](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model) for the log entry with the minimum / maximum value at the given field.
* FEATURE: add `/select/logsql/streams` HTTP endpoint for returning [streams](https://docs.victoriametrics.com/victorialogs/keyconcepts/#stream-fields) from results of the given query. See [these docs](https://docs.victoriametrics.com/victorialogs/querying/#querying-streams) for details.
* FEATURE: add `/select/logsql/stream_field_names` HTTP endpoint for returning [stream](https://docs.victoriametrics.com/victorialogs/keyconcepts/#stream-fields) field names from results of the given query. See [these docs](https://docs.victoriametrics.com/victorialogs/querying/#querying-stream-field-names) for details.
* FEATURE: add `/select/logsql/stream_field_values` HTTP endpoint for returning [stream](https://docs.victoriametrics.com/victorialogs/keyconcepts/#stream-fields) field values for the given label from results of the given query. See [these docs](https://docs.victoriametrics.com/victorialogs/querying/#querying-stream-field-values) for details.
* FEATURE: [web UI](https://docs.victoriametrics.com/victorialogs/querying/#web-ui): change time range limitation from `_time` in the expression to `start` and `end` query args.
* BUGFIX: fix `invalid memory address or nil pointer dereference` panic when using [`extract`](https://docs.victoriametrics.com/victorialogs/logsql/#extract-pipe), [`unpack_json`](https://docs.victoriametrics.com/victorialogs/logsql/#unpack_json-pipe) or [`unpack_logfmt`](https://docs.victoriametrics.com/victorialogs/logsql/#unpack_logfmt-pipe) pipes. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6306).
* BUGFIX: [web UI](https://docs.victoriametrics.com/victorialogs/querying/#web-ui): fix an issue where logs with long `_msg` values might not display. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6281).
* BUGFIX: properly handle time range boundaries with millisecond precision. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6293).
* FEATURE: add ability to extract JSON fields from [log fields](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model). See [these docs](https://docs.victoriametrics.com/victorialogs/logsql/#unpack_json-pipe).
* FEATURE: add ability to extract [logfmt](https://brandur.org/logfmt) fields from [log fields](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model). See [these docs](https://docs.victoriametrics.com/victorialogs/logsql/#unpack_logfmt-pipe).
* FEATURE: add ability to extract arbitrary text from [log fields](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model) into the output fields. See [these docs](https://docs.victoriametrics.com/victorialogs/logsql/#extract-pipe).
* FEATURE: add ability to put arbitrary [queries](https://docs.victoriametrics.com/victorialogs/logsql/#query-syntax) inside [`in()` filter](https://docs.victoriametrics.com/victorialogs/logsql/#multi-exact-filter).
* FEATURE: add support for post-filtering of query results with [`filter` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#filter-pipe).
* FEATURE: allow applying individual [filters](https://docs.victoriametrics.com/victorialogs/logsql/#filters) per each [stats function](https://docs.victoriametrics.com/victorialogs/logsql/#stats-pipe-functions). See [these docs](https://docs.victoriametrics.com/victorialogs/logsql/#stats-with-additional-filters).
* FEATURE: allow passing string values to [`min`](https://docs.victoriametrics.com/victorialogs/logsql/#min-stats) and [`max`](https://docs.victoriametrics.com/victorialogs/logsql/#max-stats) functions. Previously only numeric values could be passed to them.
* FEATURE: speed up [`sort ... limit N` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#sort-pipe) for typical cases.
* FEATURE: allow using more convenient syntax for [`range` filters](https://docs.victoriametrics.com/victorialogs/logsql/#range-filter) if upper or lower bound isn't needed. For example, it is possible to write `response_size:>=10KiB` instead of `response_size:range[10KiB, inf)`, or `temperature:<42` instead of `temperature:range(-inf, 42)`.
* FEATURE: add `/select/logsql/hits` HTTP endpoint for returning the number of matching logs per the given time bucket over the selected time range. See [these docs](https://docs.victoriametrics.com/victorialogs/querying/#querying-hits-stats) for details.
* FEATURE: add `/select/logsql/field_names` HTTP endpoint for returning [field](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model) names from results of the given query. See [these docs](https://docs.victoriametrics.com/victorialogs/querying/#querying-field-names) for details.
* FEATURE: add `/select/logsql/field_values` HTTP endpoint for returning unique values for the given [field](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model) obtained from results of the given query. See [these docs](https://docs.victoriametrics.com/victorialogs/querying/#querying-field-values) for details.
* BUGFIX: properly take into account `offset` at [`sort` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#sort-pipe) when it already has `limit`. For example, `_time:5m | sort by (foo) offset 20 limit 10`.
* FEATURE: add support for optional `start` and `end` query args to [HTTP querying API](https://docs.victoriametrics.com/victorialogs/querying/#http-api), which can be used for limiting the time range for [LogsQL query](https://docs.victoriametrics.com/victorialogs/logsql/).
* FEATURE: add ability to return the first `N` results from [`sort` pipe](#https://docs.victoriametrics.com/victorialogs/logsql/#sort-pipe). This is useful when `N` biggest or `N` smallest values must be returned from large amounts of logs.
* FEATURE: add [`quantile`](https://docs.victoriametrics.com/victorialogs/logsql/#quantile-stats) and [`median`](https://docs.victoriametrics.com/victorialogs/logsql/#median-stats) [stats functions](https://docs.victoriametrics.com/victorialogs/logsql/#stats-pipe).
* FEATURE: use [natural sort order](https://en.wikipedia.org/wiki/Natural_sort_order) when sorting logs via [`sort` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#sort-pipe).
* BUGFIX: properly return matching logs in [streams](https://docs.victoriametrics.com/victorialogs/keyconcepts/#stream-fields) with small number of entries. Previously they could be skipped. The issue has been introduced in [the release v0.6.0](https://github.com/VictoriaMetrics/VictoriaMetrics/releases/tag/v0.6.0-victorialogs).
* BUGFIX: fix `runtime error: index out of range` panic when using [`sort` pipe](https://docs.victoriametrics.com/victorialogs/logsql/#sort-pipe) like `_time:1h | sort by (_time)`. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6258).
* FEATURE: return all the log fields by default in query results. Previously only [`_stream`](https://docs.victoriametrics.com/victorialogs/keyconcepts/#stream-fields), [`_time`](https://docs.victoriametrics.com/victorialogs/keyconcepts/#time-field) and [`_msg`](https://docs.victoriametrics.com/victorialogs/keyconcepts/#message-field) fields were returned by default.
* FEATURE: add support for returning only the requested log [fields](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model). See [these docs](https://docs.victoriametrics.com/victorialogs/logsql/#fields-pipe).
* FEATURE: add support for calculating various stats over [log fields](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model). Grouping by arbitrary set of [log fields](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model) is supported. See [these docs](https://docs.victoriametrics.com/victorialogs/logsql/#stats-pipe) for details.
* FEATURE: add support for sorting the returned results. See [these docs](https://docs.victoriametrics.com/victorialogs/logsql/#sort-pipe).
* FEATURE: add support for returning unique results. See [these docs](https://docs.victoriametrics.com/victorialogs/logsql/#uniq-pipe).
* FEATURE: add support for limiting the number of returned results. See [these docs](https://docs.victoriametrics.com/victorialogs/logsql/#limiters).
* FEATURE: add support for copying and renaming the selected log fields. See [these](https://docs.victoriametrics.com/victorialogs/logsql/#copy-pipe) and [these](https://docs.victoriametrics.com/victorialogs/logsql/#rename-pipe) docs.
* FEATURE: allow using `_` inside numbers. For example, `score:range[1_000, 5_000_000]` for [`range` filter](https://docs.victoriametrics.com/victorialogs/logsql/#range-filter).
* FEATURE: allow numbers in hexadecimal and binary form. For example, `response_size:range[0xff, 0b10001101101]` for [`range` filter](https://docs.victoriametrics.com/victorialogs/logsql/#range-filter).
* FEATURE: allow using duration and byte size suffixes in numeric values inside LogsQL queries. See [these docs](https://docs.victoriametrics.com/victorialogs/logsql/#numeric-values).
* FEATURE: optimize performance for [LogsQL query](https://docs.victoriametrics.com/victorialogs/logsql/), which contains multiple filters for [words](https://docs.victoriametrics.com/victorialogs/logsql/#word-filter) or [phrases](https://docs.victoriametrics.com/victorialogs/logsql/#phrase-filter) delimited with [`AND` operator](https://docs.victoriametrics.com/victorialogs/logsql/#logical-filter). For example, `foo AND bar` query must find [log messages](https://docs.victoriametrics.com/victorialogs/keyconcepts/#message-field) with `foo` and `bar` words at faster speed.
* BUGFIX: prevent from possible corruption of short [log fields](https://docs.victoriametrics.com/victorialogs/keyconcepts/#data-model) during data ingestion.
* BUGFIX: prevent from returning log entries with empty `_stream` field in the form `"_stream":""` in [search query results](https://docs.victoriametrics.com/victorialogs/querying/). See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6042).
* BUGFIX: properly register new [log streams](https://docs.victoriametrics.com/victorialogs/keyconcepts/#stream-fields) under high data ingestion rate. The issue has been introduced in [v0.5.0](https://github.com/VictoriaMetrics/VictoriaMetrics/releases/tag/v0.5.0-victorialogs).
* BUGFIX: properly apply time range filter for queries containing [`OR` operators](https://docs.victoriametrics.com/victorialogs/logsql/#logical-filter). See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5920).
* BUGFIX: do not log debug lines `DEBUG: start trimLines` and `DEBUG: end trimLines`. This bug has been introduced in [v0.5.0](https://github.com/VictoriaMetrics/VictoriaMetrics/releases/tag/v0.5.0-victorialogs) in [this commit](https://github.com/VictoriaMetrics/VictoriaMetrics/commit/0514091948cf8e00e42f44318c0e5e5b63b6388f).
* FEATURE: support the ability to limit the number of returned log entries from [HTTP querying API](https://docs.victoriametrics.com/victorialogs/querying/#http-api) by passing `limit` query arg. Previously all the matching log entries were returned until closing the response stream. See [this feature request](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5674). Thanks to @dmitryk-dk for [the pull request](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5778).
* BUGFIX: do not panic on incorrect regular expression in [stream filter](https://docs.victoriametrics.com/victorialogs/logsql/#stream-filter). Thanks to @XLONG96 for [the bugfix](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5897).
* BUGFIX: properly determine when the assisted merge is needed. Previously the logs for determining whether the assisted merge is needed was broken. This could lead to too big number of parts under high data ingestion rate. Thanks to @lujiajing1126 for [the fix](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5447).
* BUGFIX: properly stop execution of aborted query when the query doesn't contain [`_stream` filter](https://docs.victoriametrics.com/victorialogs/logsql/#stream-filter). Previously such a query could continue consuming resources after being aborted by the client. Thanks to @z-anshun for [the fix](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5400).
* BUGFIX: properly locate logs for the [requested streams](https://docs.victoriametrics.com/victorialogs/logsql/#stream-filter). Previously logs for some streams may be missing in query results. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4856). Thanks to @XLONG96 for [the fix](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5295)!
* BUGFIX: [web UI](https://docs.victoriametrics.com/victorialogs/querying/#web-ui): properly sort found logs by time. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5300).
* BUGFIX: fix the free space verification process in VictoriaLogs that was erroneously shifting to read-only mode, despite there being sufficient free space available. See [this](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5112) issue.
* FEATURE: add `-elasticsearch.version` command-line flag, which can be used for specifying Elasticsearch version returned by VictoriaLogs to Filebeat at [elasticsearch bulk API](https://docs.victoriametrics.com/victorialogs/data-ingestion/#elasticsearch-bulk-api). This helps resolving [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4777).
* FEATURE: expose the following metrics at [/metrics](https://docs.victoriametrics.com/victorialogs/#monitoring) page:
*`vl_data_size_bytes{type="storage"}` - on-disk size for data excluding [log stream](https://docs.victoriametrics.com/victorialogs/keyconcepts/#stream-fields) indexes.
*`vl_data_size_bytes{type="indexdb"}` - on-disk size for [log stream](https://docs.victoriametrics.com/victorialogs/keyconcepts/#stream-fields) indexes.
* FEATURE: add `-insert.maxFieldsPerLine` command-line flag, which can be used for limiting the number of fields per line in logs sent to VictoriaLogs via ingestion protocols. This helps to avoid issues like [this](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4762).
* FEATURE: expose `vl_http_request_duration_seconds` histogram at the [/metrics](https://docs.victoriametrics.com/victorialogs/#monitoring) page. Thanks to @crossoverJie for [this pull request](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/4934).
* FEATURE: add support of `-storage.minFreeDiskSpaceBytes` command-line flag to allow switching to read-only mode when running out of disk space at `-storageDataPath`. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4737).
* BUGFIX: fix possible panic when no data is written to VictoriaLogs for a long time. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4895). Thanks to @crossoverJie for filing and fixing the issue.
* BUGFIX: add `/insert/loki/ready` endpoint, which is used by Promtail for healthchecks. This should remove `unsupported path requested: /insert/loki/ready` warning logs. See [this comment](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4762#issuecomment-1690966722).
* BUGFIX: prevent from panic during background merge when the number of columns in the resulting block exceeds the maximum allowed number of columns per block. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4762).
* FEATURE: add support for data ingestion via Promtail (aka default log shipper for Grafana Loki). See [these](https://docs.victoriametrics.com/victorialogs/data-ingestion/promtail/) and [these](https://docs.victoriametrics.com/victorialogs/data-ingestion/#loki-json-api) docs.
* FEATURE: support short form of `_time` filters over the last X minutes/hours/days/etc. For example, `_time:5m` is a short form for `_time:(now-5m, now]`, which matches logs with [timestamps](https://docs.victoriametrics.com/victorialogs/keyconcepts/#time-field) for the last 5 minutes. See [these docs](https://docs.victoriametrics.com/victorialogs/logsql/#time-filter) for details.
* FEATURE: add ability to specify offset for the selected time range. For example, `_time:5m offset 1h` is equivalent to `_time:(now-5m-1h, now-1h]`. See [these docs](https://docs.victoriametrics.com/victorialogs/logsql/#time-filter) for details.
* FEATURE: [LogsQL](https://docs.victoriametrics.com/victorialogs/logsql/): replace `exact_prefix("...")` with `exact("..."*)`. This makes it consistent with [i()](https://docs.victoriametrics.com/victorialogs/logsql/#case-insensitive-filter) filter, which can accept phrases and prefixes, e.g. `i("phrase")` and `i("phrase"*)`. See [these docs](https://docs.victoriametrics.com/victorialogs/logsql/#exact-prefix-filter).
