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MDEV-28699 Shrink temporary tablespaces without restart

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- Introduced the variable "innodb_truncate_temporary_tablespace_now"
to shrink the temporary tablespace.

Steps for shrinking the temporary tablespace:

1) Find the last used extent in temporary tablespace
by iterating through the BITMAP in extent descriptor pages

2) If the last used extent is lesser than user specified size
then set desired target size to user specified size

3) Store the page contents of "to be modified" extent
descriptor pages, latches the "to be modified" extent
descriptor pages and check for buffer pool memory availability

4) Update the FSP_SIZE and FSP_FREE_LIMIT in header page

5) Remove the "to be truncated" pages from FSP_FREE and
FSP_FREE_FRAG list

6) Reset the bitmap in the last descriptor pages for the
"to be truncated" pages.

7) Clear the freed range in temporary tablespace which
are to be truncated.

8) Evict the "to be truncated" temporary tablespace pages
from LRU list.

9) In case of multiple files, calculate the truncated last
file size and do truncation in last file

10) Commit the mini-transaction for shrinking the tablespace
This commit is contained in:
Thirunarayanan Balathandayuthapani
2023-09-12 17:37:08 +05:30
committed by Marko Mäkelä
parent 7b842f1536
commit c507678b20
14 changed files with 371 additions and 24 deletions
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22
mysql-test/suite/innodb/r/temp_truncate_debug.result Normal file
View File

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call mtr.add_suppression("InnoDB: Cannot shrink the temporary tablespace");
# restart
SET GLOBAL INNODB_LIMIT_OPTIMISTIC_INSERT_DEBUG=2;
CREATE TEMPORARY TABLE t1(f1 INT NOT NULL,
f2 INT NOT NULL)ENGINE=InnoDB;
INSERT INTO t1 SELECT seq, seq FROM seq_1_to_65536;
DROP TABLE t1;
SELECT NAME, FILE_SIZE FROM INFORMATION_SCHEMA.INNODB_SYS_TABLESPACES WHERE SPACE= 4294967294;
NAME FILE_SIZE
innodb_temporary 1146093568
SET @saved_debug_dbug = @@SESSION.debug_dbug;
SET DEBUG_DBUG="+d,fail_temp_truncate";
SET GLOBAL INNODB_TRUNCATE_TEMPORARY_TABLESPACE_NOW= 1;
SELECT NAME, FILE_SIZE FROM INFORMATION_SCHEMA.INNODB_SYS_TABLESPACES WHERE SPACE= 4294967294;
NAME FILE_SIZE
innodb_temporary 1146093568
SET DEBUG_DBUG=@saved_debug_dbug;
SET GLOBAL INNODB_TRUNCATE_TEMPORARY_TABLESPACE_NOW= 1;
SELECT NAME, FILE_SIZE FROM INFORMATION_SCHEMA.INNODB_SYS_TABLESPACES WHERE SPACE= 4294967294;
NAME FILE_SIZE
innodb_temporary 5242880
SET GLOBAL INNODB_LIMIT_OPTIMISTIC_INSERT_DEBUG=default;