| Bug #33473 | MEMORY engine doesn't honor MAX_ROWS correctly | ||
|---|---|---|---|
| Submitted: | 21 Dec 2007 21:35 | Modified: | 22 Dec 2007 21:30 |
| Reporter: | Jorge Bernal | Email Updates: | |
| Status: | Not a Bug | Impact on me: | |
| Category: | MySQL Server: Memory storage engine | Severity: | S3 (Non-critical) |
| Version: | 5.1.22 | OS: | MacOS |
| Assigned to: | CPU Architecture: | Any | |
[22 Dec 2007 20:23]
MySQL Verification Team
Thank you for the bug report. Please read the Manual: http://dev.mysql.com/doc/refman/5.1/en/create-table.html "MAX_ROWS The maximum number of rows you plan to store in the table. This is not a hard limit, but rather a hint to the storage engine that the table must be able to store at least this many rows."
[22 Dec 2007 21:30]
Jorge Bernal
I know it's approximate. In MyISAM, a MAX_ROWS of 10 converts to a real limit of 65535 rows. The strange thing here is having Data_length greater than Max_data_length. I think that souldn't be possible
Description: When you create a table with MAX_ROWS set to 10, you can still insert 20 rows. And "Data_length" is higher than "Max_data_length" in SHOW TABLE STATUS How to repeat: mysql> create table tm (c1 INT) engine=memory max_rows=10; Query OK, 0 rows affected (0.01 sec) mysql> insert into tm values (),(),(),(),(),(),(),(); Query OK, 8 rows affected (0.00 sec) Records: 8 Duplicates: 0 Warnings: 0 mysql> insert into tm select NULL from tm t1,tm t2,tm t3; ERROR 1114 (HY000): The table 'tm' is full mysql> select count(*) from tm; +----------+ | count(*) | +----------+ | 20 | +----------+ 1 row in set (0.00 sec) mysql> show table status like 'tm'\G *************************** 1. row *************************** Name: tm Engine: MEMORY Version: 10 Row_format: Fixed Rows: 20 Avg_row_length: 5 Data_length: 672 Max_data_length: 50 Index_length: 0 Data_free: 0 Auto_increment: NULL Create_time: NULL Update_time: NULL Check_time: NULL Collation: latin1_swedish_ci Checksum: NULL Create_options: max_rows=10 Comment: 1 row in set (0.00 sec)