diff options
Diffstat (limited to 'sql/ha_berkeley.cc')
| -rw-r--r-- | sql/ha_berkeley.cc | 26 |
1 files changed, 22 insertions, 4 deletions
diff --git a/sql/ha_berkeley.cc b/sql/ha_berkeley.cc index 6cf97f16bb8..490a6db89e5 100644 --- a/sql/ha_berkeley.cc +++ b/sql/ha_berkeley.cc @@ -25,8 +25,9 @@ We will need an updated Berkeley DB version for this. - Killing threads that has got a 'deadlock' - SHOW TABLE STATUS should give more information about the table. - - Get a more accurate count of the number of rows. - We could store the found number of rows when the table is scanned. + - Get a more accurate count of the number of rows (estimate_number_of_rows()). + We could store the found number of rows when the table is scanned and + then increment the counter for each attempted write. - We will need a manager thread that calls flush_logs, removes old logs and makes checkpoints at given intervals. - When not using UPDATE IGNORE, don't make a sub transaction but abort @@ -42,7 +43,6 @@ - LOCK TABLES - CHAR keys - BLOBS - - delete from t1; */ @@ -60,6 +60,7 @@ #define HA_BERKELEY_ROWS_IN_TABLE 10000 /* to get optimization right */ #define HA_BERKELEY_RANGE_COUNT 100 +#define HA_BERKELEY_MAX_ROWS 10000000 /* Max rows in table */ const char *ha_berkeley_ext=".db"; bool berkeley_skip=0; @@ -1297,7 +1298,7 @@ void ha_berkeley::info(uint flag) DBUG_ENTER("info"); if (flag & HA_STATUS_VARIABLE) { - records = HA_BERKELEY_ROWS_IN_TABLE; // Just to get optimisations right + records = estimate_number_of_rows(); // Just to get optimisations right deleted = 0; } else if (flag & HA_STATUS_ERRKEY) @@ -1607,4 +1608,21 @@ void ha_berkeley::update_auto_primary_key() pthread_mutex_unlock(&share->mutex); } +/* + Return an estimated of the number of rows in the table. + Used when sorting to allocate buffers and by the optimizer. +*/ + +ha_rows ha_berkeley::estimate_number_of_rows() +{ + ulonglong max_ident; + ulonglong max_rows=table->max_rows ? table->max_rows : HA_BERKELEY_MAX_ROWS; + if (!hidden_primary_key) + return (ha_rows) max_rows; + pthread_mutex_lock(&share->mutex); + max_ident=share->auto_ident+EXTRA_RECORDS; + pthread_mutex_unlock(&share->mutex); + return (ha_rows) min(max_ident,max_rows); +} + #endif /* HAVE_BERKELEY_DB */ |