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Fixed memory leak when using histograms

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This was introduced in last merge with 10.6
The reason is that 10.6 does not need anything special to free histograms
as everything is allocated on a memroot.
In 10.10 histograms is using the vector class, which has some problems:
- No automatic free
- No memory usage accounting
(we should at some point remove vector usage because of the above problem)

Fixed by expliciting freeing histograms when freeing TABLE_STATISTICS
objects.
This commit is contained in:
Monty
2023-10-16 17:14:24 +03:00
parent 0563106b1a
commit a49ebf71af
2 changed files with 14 additions and 1 deletions
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13
sql/sql_statistics.cc
View File

@ -91,7 +91,19 @@ TABLE_STATISTICS_CB::TABLE_STATISTICS_CB():
TABLE_STATISTICS_CB::~TABLE_STATISTICS_CB()
{
Column_statistics *column_stats= table_stats->column_stats;
Column_statistics *column_stats_end= column_stats + table_stats->columns;
DBUG_ASSERT(usage_count == 0);
/* Free json histograms */
for (; column_stats < column_stats_end ; column_stats++)
{
delete column_stats->histogram;
/*
Protect against possible other free in free_statistics_for_table()
*/
column_stats->histogram= 0;
}
free_root(&mem_root, MYF(0));
}
@ -2381,6 +2393,7 @@ alloc_engine_independent_statistics(THD *thd, const TABLE_SHARE *table_share,
bzero(idx_avg_frequency, sizeof(idx_avg_frequency) * key_parts);
stats_cb->table_stats= table_stats;
table_stats->columns= table_share->fields;
table_stats->column_stats= column_stats;
table_stats->index_stats= index_stats;
table_stats->idx_avg_frequency= idx_avg_frequency;

2
sql/sql_statistics.h
View File

@ -432,9 +432,9 @@ class Index_statistics;
class Table_statistics
{
public:
my_bool cardinality_is_null; /* TRUE if the cardinality is unknown */
uint columns; /* Number of columns in table */
ha_rows cardinality; /* Number of rows in the table */
uchar *min_max_record_buffers; /* Record buffers for min/max values */
Column_statistics *column_stats; /* Array of statistical data for columns */