diff options
| author | heikki@hundin.mysql.fi <> | 2002-10-05 22:23:51 +0300 |
|---|---|---|
| committer | heikki@hundin.mysql.fi <> | 2002-10-05 22:23:51 +0300 |
| commit | cc1db6142fcb3a09b6b132d8a7c6a800a2e62c63 (patch) | |
| tree | 1f65a91a8476086670563c066d7ad49e045cce3d /innobase | |
| parent | a9c9856f26c510bf8026f58110d34c5283207bd1 (diff) | |
| download | mariadb-git-cc1db6142fcb3a09b6b132d8a7c6a800a2e62c63.tar.gz | |
btr0cur.c:
Do not let range estimator to return over 1 / 2 of total rows in table; use longlong in range estimation
btr0cur.h, ha_innobase.cc:
Use longlong in range estimation, in case there are > 4 billion rows
Diffstat (limited to 'innobase')
| -rw-r--r-- | innobase/btr/btr0cur.c | 20 | ||||
| -rw-r--r-- | innobase/include/btr0cur.h | 2 |
2 files changed, 19 insertions, 3 deletions
diff --git a/innobase/btr/btr0cur.c b/innobase/btr/btr0cur.c index 8abf918366a..6cf3d640aa0 100644 --- a/innobase/btr/btr0cur.c +++ b/innobase/btr/btr0cur.c @@ -2531,7 +2531,7 @@ btr_cur_add_path_info( /*********************************************************************** Estimates the number of rows in a given index range. */ -ulint +ib_longlong btr_estimate_n_rows_in_range( /*=========================*/ /* out: estimated number of rows */ @@ -2548,7 +2548,7 @@ btr_estimate_n_rows_in_range( btr_path_t* slot2; ibool diverged; ulint divergence_level; - ulint n_rows; + ib_longlong n_rows; ulint i; mtr_t mtr; @@ -2608,6 +2608,22 @@ btr_estimate_n_rows_in_range( n_rows = n_rows * 2; } + + /* Do not estimate the number of rows in the range + to over 1 / 2 of the estimated rows in the whole + table */ + + if (n_rows > index->table->stat_n_rows / 2) { + n_rows = index->table->stat_n_rows / 2; + + /* If there are just 0 or 1 rows in the table, + then we estimate all rows are in the range */ + + if (n_rows == 0) { + n_rows = index->table->stat_n_rows; + } + } + return(n_rows); } diff --git a/innobase/include/btr0cur.h b/innobase/include/btr0cur.h index b01cbd9a875..7039ceba245 100644 --- a/innobase/include/btr0cur.h +++ b/innobase/include/btr0cur.h @@ -417,7 +417,7 @@ btr_cur_parse_del_mark_set_sec_rec( /*********************************************************************** Estimates the number of rows in a given index range. */ -ulint +ib_longlong btr_estimate_n_rows_in_range( /*=========================*/ /* out: estimated number of rows */ |