lib/logstorage: support order alias for sort pipe

Now the following queries are equivalents:

    _time:5s | sort by (_time)

    _time:5s | order by (_time)

This is needed for convenience, since `order by` is commonly used in other query languages such as SQL.

docs/VictoriaLogs/CHANGELOG.md

@@ -16,6 +16,7 @@ according to [these docs](https://docs.victoriametrics.com/victorialogs/quicksta
 ## tip
 
 * FEATURE: [data ingestion](https://docs.victoriametrics.com/victorialogs/data-ingestion/): accept Unix timestamps in seconds in the ingested logs.
+* 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)`.
 
 ## [v0.31.0](https://github.com/VictoriaMetrics/VictoriaMetrics/releases/tag/v0.31.0-victorialogs)
 

docs/VictoriaLogs/LogsQL.md

@@ -2110,6 +2110,12 @@ The `by` keyword can be skipped in `sort ...` pipe. For example, the following q
 _time:5m | sort (foo, bar) desc
 ```
 
+The `order` alias can be used instead of `sort`, so the following query is equivalent to the previous one:
+
+```logsql
+_time:5m | order by (foo, bar) desc
+```
+
 Sorting of big number of logs can consume a lot of CPU time and memory. Sometimes it is enough to return the first `N` entries with the biggest
 or the smallest values. This can be done by adding `limit N` to the end of `sort ...` pipe.
 Such a query consumes lower amounts of memory when sorting big number of logs, since it keeps in memory only `N` log entries.

lib/logstorage/parser_test.go

@@ -1150,9 +1150,11 @@ func TestParseQuerySuccess(t *testing.T) {
 
 	// sort pipe
 	f(`* | sort`, `* | sort`)
+	f(`* | order`, `* | sort`)
 	f(`* | sort desc`, `* | sort desc`)
 	f(`* | sort by()`, `* | sort`)
 	f(`* | sort bY (foo)`, `* | sort by (foo)`)
+	f(`* | ORDer bY (foo)`, `* | sort by (foo)`)
 	f(`* | sORt bY (_time, _stream DEsc, host)`, `* | sort by (_time, _stream desc, host)`)
 	f(`* | sort bY (foo desc, bar,) desc`, `* | sort by (foo desc, bar) desc`)
 	f(`* | sort limit 10`, `* | sort limit 10`)

lib/logstorage/pipe.go

@@ -213,7 +213,7 @@ func parsePipe(lex *lexer) (pipe, error) {
 			return nil, fmt.Errorf("cannot parse 'replace_regexp' pipe: %w", err)
 		}
 		return pr, nil
-	case lex.isKeyword("sort"):
+	case lex.isKeyword("sort"), lex.isKeyword("order"):
 		ps, err := parsePipeSort(lex)
 		if err != nil {
 			return nil, fmt.Errorf("cannot parse 'sort' pipe: %w", err)
@@ -309,7 +309,7 @@ var pipeNames = func() map[string]struct{} {
 		"rename", "mv",
 		"replace",
 		"replace_regexp",
-		"sort",
+		"sort", "order",
 		"stats",
 		"stream_context",
 		"top",

lib/logstorage/pipe_sort.go

@@ -748,8 +748,8 @@ func sortBlockLess(shardA *pipeSortProcessorShard, rowIdxA int, shardB *pipeSort
 }
 
 func parsePipeSort(lex *lexer) (*pipeSort, error) {
-	if !lex.isKeyword("sort") {
+	if !lex.isKeyword("sort") && !lex.isKeyword("order") {
-		return nil, fmt.Errorf("expecting 'sort'; got %q", lex.token)
+		return nil, fmt.Errorf("expecting 'sort' or 'order'; got %q", lex.token)
 	}
 	lex.nextToken()
 

lib/logstorage/pipe_sort_test.go

@@ -308,7 +308,7 @@ func TestPipeSort(t *testing.T) {
 	})
 
 	// Sort by multiple fields with offset and limit
-	f("sort by (a, b) desc offset 2 limit 100", [][]Field{
+	f("order by (a, b) desc offset 2 limit 100", [][]Field{
 		{
 			{"_msg", `abc`},
 			{"a", `2`},
@@ -360,5 +360,5 @@ func TestPipeSortUpdateNeededFields(t *testing.T) {
 
 	// needed fields intersect with src
 	f("sort by(s1,s2)", "s1,f1,f2", "", "s1,s2,f1,f2", "")
-	f("sort by(s1,s2) rank as x", "s1,f1,f2,x", "", "s1,s2,f1,f2", "")
+	f("order by(s1,s2) rank as x", "s1,f1,f2,x", "", "s1,s2,f1,f2", "")
 }