stats: table setting to turn auto stats collection on/off

[cockroach-teamcity]

Exalate commented:

Related PR: cockroachdb/cockroach#78110
Commit: cockroachdb/cockroach@f9a102d

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Release note (sql change): Automatic statistics collection can now be
enabled or disabled for individual tables, taking precedence over the
cluster setting, for example:

ALTER TABLE t1 SET (sql_stats_automatic_collection_enabled = true);
ALTER TABLE t1 SET (sql_stats_automatic_collection_enabled = false);
ALTER TABLE t1 RESET (sql_stats_automatic_collection_enabled);

RESET removes the setting value entirely, in which case the
similarly-name cluster setting,
sql.stats.automatic_collection.enabled, is in effect for the table.

Cluster settings sql.stats.automatic_collection.fraction_stale_rows
and sql.stats.automatic_collection.min_stale_rows now also have table
setting counterparts:

sql_stats_automatic_collection_fraction_stale_rows
sql_stats_automatic_collection_min_stale_rows

The table settings may be set at table creation time, or later via ALTER
TABLE ... SET, independent of whether auto stats is enabled:

ALTER TABLE t1
      SET (sql_stats_automatic_collection_fraction_stale_rows = 0.1,
           sql_stats_automatic_collection_min_stale_rows = 2000);
CREATE TABLE t1 (a INT, b INT)
       WITH (sql_stats_automatic_collection_enabled = true,
             sql_stats_automatic_collection_min_stale_rows = 1000000,
             sql_stats_automatic_collection_fraction_stale_rows= 0.05
             );

The current table settings (storage parameters) are shown in the WITH
clause output of SHOW CREATE TABLE.
Note, any row mutations which have occurred a minute or two before
disabling auto stats collection via ALTER TABLE ... SET may trigger
stats collection, though DML submitted after the setting change will
not.

Jira Issue: DOC-3511