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Code Activity

MDEV-5675 - Performance: my_hash_sort_bin is called too often

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Reduced number of my_hash_sort_bin() calls from 4 to 1 per query.
Reduced number of memory accesses done by my_hash_sort_bin().

Details:
- let MDL subsystem use pre-calculated hash value for hash
  inserts and deletes
- let table cache use pre-calculated MDL hash value
- MDL namespace is excluded from hash value calculation, so that
  hash value can be used by table cache as is
- hash value for MDL is calculated as resulting hash value + MDL
  namespace
- extended hash implementation to accept user defined hash function
This commit is contained in:
Sergey Vojtovich
2014-03-06 16:19:12 +04:00
parent ae87e63184
commit b95c8ce530
13 changed files with 99 additions and 69 deletions
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8
mysql-test/r/create_or_replace.result
View File

@@ -333,29 +333,29 @@ lock table t1 write, t2 read;
select * from information_schema.metadata_lock_info;
THREAD_ID LOCK_MODE LOCK_DURATION LOCK_TYPE TABLE_SCHEMA TABLE_NAME
# MDL_INTENTION_EXCLUSIVE MDL_EXPLICIT Global read lock
# MDL_INTENTION_EXCLUSIVE MDL_EXPLICIT Schema metadata lock test
# MDL_SHARED_NO_READ_WRITE MDL_EXPLICIT Table metadata lock test t1
# MDL_INTENTION_EXCLUSIVE MDL_EXPLICIT Schema metadata lock test
# MDL_SHARED_READ MDL_EXPLICIT Table metadata lock test t2
create or replace table t1 (i int);
select * from information_schema.metadata_lock_info;
THREAD_ID LOCK_MODE LOCK_DURATION LOCK_TYPE TABLE_SCHEMA TABLE_NAME
# MDL_INTENTION_EXCLUSIVE MDL_EXPLICIT Global read lock
# MDL_INTENTION_EXCLUSIVE MDL_EXPLICIT Schema metadata lock test
# MDL_SHARED_NO_READ_WRITE MDL_EXPLICIT Table metadata lock test t1
# MDL_INTENTION_EXCLUSIVE MDL_EXPLICIT Schema metadata lock test
# MDL_SHARED_READ MDL_EXPLICIT Table metadata lock test t2
create or replace table t1 like t2;
select * from information_schema.metadata_lock_info;
THREAD_ID LOCK_MODE LOCK_DURATION LOCK_TYPE TABLE_SCHEMA TABLE_NAME
# MDL_INTENTION_EXCLUSIVE MDL_EXPLICIT Global read lock
# MDL_INTENTION_EXCLUSIVE MDL_EXPLICIT Schema metadata lock test
# MDL_SHARED_NO_READ_WRITE MDL_EXPLICIT Table metadata lock test t1
# MDL_INTENTION_EXCLUSIVE MDL_EXPLICIT Schema metadata lock test
# MDL_SHARED_READ MDL_EXPLICIT Table metadata lock test t2
create or replace table t1 select 1 as f1;
select * from information_schema.metadata_lock_info;
THREAD_ID LOCK_MODE LOCK_DURATION LOCK_TYPE TABLE_SCHEMA TABLE_NAME
# MDL_INTENTION_EXCLUSIVE MDL_EXPLICIT Global read lock
# MDL_INTENTION_EXCLUSIVE MDL_EXPLICIT Schema metadata lock test
# MDL_SHARED_NO_READ_WRITE MDL_EXPLICIT Table metadata lock test t1
# MDL_INTENTION_EXCLUSIVE MDL_EXPLICIT Schema metadata lock test
# MDL_SHARED_READ MDL_EXPLICIT Table metadata lock test t2
drop table t1;
unlock tables;