sql: enable indexing and ordering on arrays of orderable and indexabl…

…e types

Fixes #17154.
Fixes #35707.

This PR enables arrays to be ordered and indexed by
introducing an ordered key encoding for arrays.
Once this exists, the rest of the SQL infrastructure
is ready to handle indexing and ordering on arrays.

To encode an array of elements `ARRAY[a, b]`,
we create the following encoding.

Let `AM` = a marker byte for arrays and let `AT` be a terminator byte.

`enc(ARRAY[a, b]) = [AM, enc(a), enc(b), AT]`

The key is that the terminator is less than the element marker.
This allows for the "prefix matching" style comparison that
arrays support.

Release note (sql change): This PR adds support for indexing
and ordering of arrays of indexable and orderable inner types.

pkg/sql/execinfra/server_config.go

@@ -62,11 +62,11 @@ import (
 //
 // ATTENTION: When updating these fields, add to version_history.txt explaining
 // what changed.
-const Version execinfrapb.DistSQLVersion = 28
+const Version execinfrapb.DistSQLVersion = 29
 
 // MinAcceptedVersion is the oldest version that the server is
 // compatible with; see above.
-const MinAcceptedVersion execinfrapb.DistSQLVersion = 27
+const MinAcceptedVersion execinfrapb.DistSQLVersion = 29
 
 // SettingWorkMemBytes is a cluster setting that determines the maximum amount
 // of RAM that a processor can use.

pkg/sql/flowinfra/stream_encoder.go

@@ -105,7 +105,7 @@ func (se *StreamEncoder) AddRow(row sqlbase.EncDatumRow) error {
 			if !ok {
 				enc = PreferredEncoding
 			}
-			sType := se.infos[i].Type.Family()
+			sType := se.infos[i].Type
 			if enc != sqlbase.DatumEncoding_VALUE &&
 				(sqlbase.HasCompositeKeyEncoding(sType) || sqlbase.MustBeValueEncoded(sType)) {
 				// Force VALUE encoding for composite types (key encodings may lose data).

pkg/sql/logictest/testdata/logic_test/alter_table

@@ -798,25 +798,6 @@ decomputed_column  CREATE TABLE decomputed_column (
 statement ok
 CREATE TABLE b26483()
 
-statement error unimplemented: column c is of type int\[\] and thus is not indexable
-ALTER TABLE b26483 ADD COLUMN c INT[] UNIQUE
-
-# As above, but performed in a transaction
-statement ok
-BEGIN
-
-statement ok
-CREATE TABLE b26483_tx()
-
-statement ok
-ALTER TABLE b26483_tx ADD COLUMN c INT[]
-
-statement error unimplemented: column c is of type int\[\] and thus is not indexable
-CREATE INDEX on b26483_tx (c)
-
-statement ok
-ROLLBACK
-
 # Verify that auditing can be enabled by root, and cannot be disabled by non-root.
 
 statement ok