Small corrections to MDEV-29693 ANALYZE TABLE

32 bit MariaDB crashed in innodb.innodb-16k and a few other tests.
Fixed by using correct sizeof() calls.

Histograms where not read if first read was without histograms.

mysql-test/main/stat_tables_flush.result

@@ -87,5 +87,76 @@ test.t1	analyze	status	Engine-independent statistics collected
 test.t1	analyze	status	OK
 drop table t1;
 #
-# End of 10.5 tests
+# Test that histograms are read after flush
+#
+create table t1 (a int);
+insert into t1 select seq from seq_1_to_10;
+insert into t1 select A.seq from seq_10_to_20 A, seq_1_to_9 B;
+analyze table t1 persistent for all;
+Table	Op	Msg_type	Msg_text
+test.t1	analyze	status	Engine-independent statistics collected
+test.t1	analyze	status	OK
+explain format=json select * from t1 where a between 2 and 5;
+EXPLAIN
+{
+  "query_block": {
+    "select_id": 1,
+    "table": {
+      "table_name": "t1",
+      "access_type": "ALL",
+      "rows": 109,
+      "filtered": 5,
+      "attached_condition": "t1.a between 2 and 5"
+    }
+  }
+}
+explain format=json select * from t1 where a between 12 and 15;
+EXPLAIN
+{
+  "query_block": {
+    "select_id": 1,
+    "table": {
+      "table_name": "t1",
+      "access_type": "ALL",
+      "rows": 109,
+      "filtered": 33.59375,
+      "attached_condition": "t1.a between 12 and 15"
+    }
+  }
+}
+flush tables;
+set @@optimizer_use_condition_selectivity=3;
+explain format=json select * from t1 where a between 2 and 5;
+EXPLAIN
+{
+  "query_block": {
+    "select_id": 1,
+    "table": {
+      "table_name": "t1",
+      "access_type": "ALL",
+      "rows": 109,
+      "filtered": 15.78947353,
+      "attached_condition": "t1.a between 2 and 5"
+    }
+  }
+}
+set @@optimizer_use_condition_selectivity=4;
+explain format=json select * from t1 where a between 2 and 5;
+EXPLAIN
+{
+  "query_block": {
+    "select_id": 1,
+    "table": {
+      "table_name": "t1",
+      "access_type": "ALL",
+      "rows": 109,
+      "filtered": 5,
+      "attached_condition": "t1.a between 2 and 5"
+    }
+  }
+}
+drop table t1;
+set @@optimizer_use_condition_selectivity=default;
+#
+# End of 10.6 tests
 #

mysql-test/main/stat_tables_flush.test

@@ -46,5 +46,27 @@ analyze table t1 persistent for all;
 drop table t1;
 
 --echo #
---echo # End of 10.5 tests
+--echo # Test that histograms are read after flush
+--echo #
+
+create table t1 (a int);
+insert into t1 select seq from seq_1_to_10;
+
+insert into t1 select A.seq from seq_10_to_20 A, seq_1_to_9 B;
+analyze table t1 persistent for all;
+
+explain format=json select * from t1 where a between 2 and 5;
+explain format=json select * from t1 where a between 12 and 15;
+
+flush tables;
+set @@optimizer_use_condition_selectivity=3;
+explain format=json select * from t1 where a between 2 and 5;
+set @@optimizer_use_condition_selectivity=4;
+explain format=json select * from t1 where a between 2 and 5;
+
+drop table t1;
+set @@optimizer_use_condition_selectivity=default;
+
+--echo #
+--echo # End of 10.6 tests
 --echo #

sql/sql_statistics.cc

@@ -2102,7 +2102,7 @@ int alloc_statistics_for_table(THD* thd, TABLE *table)
                         &column_stats, sizeof(*column_stats) * fields,
                         &index_stats, sizeof(*index_stats) * keys,
                         &idx_avg_frequency,
-                        sizeof(idx_avg_frequency) * key_parts,
+                        sizeof(*idx_avg_frequency) * key_parts,
                         &histogram, hist_size * fields,
                         NullS))
     DBUG_RETURN(1);
@@ -2145,6 +2145,14 @@ int alloc_statistics_for_table(THD* thd, TABLE *table)
     key_info->collected_stats->init_avg_frequency(idx_avg_frequency);
     idx_avg_frequency+= key_info->ext_key_parts;
   }
+  /*
+    idx_avg_frequency can be less than
+    table_stats->idx_avg_frequency + key_parts
+    in the case of LONG_UNIQUE_HASH_FIELD as these has a hidden
+    ext_key_part which is counted in table_share->ext_keyparts but not
+    in keyinfo->ext_key_parts.
+  */
+  DBUG_ASSERT(idx_avg_frequency <= table_stats->idx_avg_frequency + key_parts);
 
   create_min_max_statistical_fields_for_table(thd, table);
 
@@ -2208,7 +2216,7 @@ alloc_engine_independent_statistics(THD *thd, const TABLE_SHARE *table_share,
                         &column_stats, sizeof(Column_statistics) * fields,
                         &index_stats, sizeof(Index_statistics) * keys,
                         &idx_avg_frequency,
-                        sizeof(idx_avg_frequency) * key_parts,
+                        sizeof(*idx_avg_frequency) * key_parts,
                         NullS))
     DBUG_RETURN(1);
 
@@ -2232,6 +2240,7 @@ alloc_engine_independent_statistics(THD *thd, const TABLE_SHARE *table_share,
     index_stats->init_avg_frequency(idx_avg_frequency);
     idx_avg_frequency+= key_info->ext_key_parts;
   }
+  DBUG_ASSERT(idx_avg_frequency <= table_stats->idx_avg_frequency + key_parts);
   DBUG_RETURN(0);
 }
 
@@ -2840,11 +2849,12 @@ read_statistics_for_table(THD *thd, TABLE *table,
   TABLE_SHARE *table_share= table->s;
   DBUG_ENTER("read_statistics_for_table");
 
-  if (!force_reload && table_share->stats_cb)
+  if (!force_reload && table_share->stats_cb &&
+      (!want_histograms || !table_share->histograms_exists()))
   {
     if (table->stats_cb == table_share->stats_cb)
-      DBUG_RETURN(table->stats_cb);      // Use current
+      DBUG_RETURN(table->stats_cb);		// Use current
-    table->update_engine_independent_stats();        // Copy table_share->stats_cb
+    table->update_engine_independent_stats();	// Copy table_share->stats_cb
     DBUG_RETURN(table->stats_cb);
   }
 

sql/table.cc

@@ -4596,6 +4596,22 @@ TABLE_SHARE::update_engine_independent_stats(TABLE_STATISTICS_CB *new_stats)
 }
 
 
+/* Check if we have statistics for histograms */
+
+bool TABLE_SHARE::histograms_exists()
+{
+  bool res= 0;
+  if (stats_cb)
+  {
+    mysql_mutex_lock(&LOCK_share);
+    if (stats_cb)
+      res= stats_cb->histograms_exists();
+    mysql_mutex_unlock(&LOCK_share);
+  }
+  return res;
+}
+
+
 /*
   Free information allocated by openfrm
 

sql/table.h

@@ -1161,6 +1161,7 @@ struct TABLE_SHARE
                                       MEM_ROOT *mem_root,
                                       List<Item> *field_list) const;
   void update_engine_independent_stats(TABLE_STATISTICS_CB *stat);
+  bool histograms_exists();
 };
 
 /* not NULL, but cannot be dereferenced */