mirror of
https://github.com/MariaDB/server.git
synced 2025-01-15 19:42:28 +01:00
52c29f3bdc
Heap tables are allocated blocks to store rows according to my_default_record_cache (mapped to the server global variable read_buffer_size). This causes performance issues when the record length is big (> 1000 bytes) and the my_default_record_cache is small. Changed to instead split the default heap allocation to 1/16 of the allowed space and not use my_default_record_cache anymore when creating the heap. The allocation is also aligned to be just under a power of 2. For some test that I have been running, which was using record length=633, the speed of the query doubled thanks to this change. Other things: - Fixed calculation of max_records passed to hp_create() to take into account padding between records. - Updated calculation of memory needed by heap tables. Before we did not take into account internal structures needed to access rows. - Changed block sized for memory_table from 1 to 16384 to get less fragmentation. This also avoids a problem where we need 1K to manage index and row storage which was not counted for before. - Moved heap memory usage to a separate test for 32 bit. - Allocate all data blocks in heap in powers of 2. Change reported memory usage for heap to reflect this. Reviewed-by: Sergei Golubchik <serg@mariadb.org> |
||
|---|---|---|
| .. | ||
| archive | ||
| blackhole | ||
| columnstore | ||
| connect | ||
| csv | ||
| example | ||
| federated | ||
| federatedx | ||
| heap | ||
| innobase | ||
| maria | ||
| mroonga | ||
| myisam | ||
| myisammrg | ||
| oqgraph | ||
| perfschema | ||
| rocksdb | ||
| sequence | ||
| sphinx | ||
| spider | ||
| test_sql_discovery | ||