MDEV-21472: ALTER TABLE ... ANALYZE PARTITION ... with EITS reads and locks all rows

Do not collect EITS statistics for this statement:

  ALTER TABLE t ANALYZE PARTITION p

EITS stats are currently global, not per-partition.
Collecting global stats when we are asked to process just one partition
causes issues for DBAs.

1 files changed, 10 insertions, 0 deletions

diff --git a/sql/sql_admin.cc b/sql/sql_admin.cc
index 4afaff58223..beecf3fae64 100644
--- a/sql/sql_admin.cc
+++ b/sql/sql_admin.cc
@@ -727,8 +727,18 @@ static bool mysql_admin_table(THD* thd, TABLE_LIST* tables,
       {
         compl_result_code= result_code= HA_ADMIN_INVALID;
       }
+
+      /*
+        The check for Alter_info::ALTER_ADMIN_PARTITION implements this logic:
+        do not collect EITS STATS for this syntax:
+          ALTER TABLE ... ANALYZE PARTITION p
+        EITS statistics is global (not per-partition). Collecting global stats
+        is much more expensive processing just one partition, so the most
+        appropriate action is to just not collect EITS stats for this command.
+      */
       collect_eis=
         (table->table->s->table_category == TABLE_CATEGORY_USER &&
+        !(lex->alter_info.flags &= Alter_info::ALTER_ADMIN_PARTITION) &&
          (get_use_stat_tables_mode(thd) > NEVER ||
           lex->with_persistent_for_clause));