mirror of
https://github.com/MariaDB/server.git
synced 2025-08-07 00:04:31 +03:00
Merge baker@bk-internal.mysql.com:/home/bk/mysql-4.1
into zim.(none):/home/brian/mysql/mysql-4.1 sql/examples/ha_archive.cc: Auto merged
This commit is contained in:
@@ -33,6 +33,7 @@ bk@mysql.r18.ru
|
|||||||
brian@avenger.(none)
|
brian@avenger.(none)
|
||||||
brian@brian-akers-computer.local
|
brian@brian-akers-computer.local
|
||||||
brian@private-client-ip-101.oz.net
|
brian@private-client-ip-101.oz.net
|
||||||
|
brian@zim.(none)
|
||||||
carsten@tsort.bitbybit.dk
|
carsten@tsort.bitbybit.dk
|
||||||
davida@isil.mysql.com
|
davida@isil.mysql.com
|
||||||
dellis@goetia.(none)
|
dellis@goetia.(none)
|
||||||
|
@@ -42,18 +42,20 @@
|
|||||||
handle bulk inserts as well (that is if someone was trying to read at
|
handle bulk inserts as well (that is if someone was trying to read at
|
||||||
the same time since we would want to flush).
|
the same time since we would want to flush).
|
||||||
|
|
||||||
A "meta" file is kept. All this file does is contain information on
|
A "meta" file is kept alongside the data file. This file serves two purpose.
|
||||||
the number of rows.
|
The first purpose is to track the number of rows in the table. The second
|
||||||
|
purpose is to determine if the table was closed properly or not. When the
|
||||||
|
meta file is first opened it is marked as dirty. It is opened when the table
|
||||||
|
itself is opened for writing. When the table is closed the new count for rows
|
||||||
|
is written to the meta file and the file is marked as clean. If the meta file
|
||||||
|
is opened and it is marked as dirty, it is assumed that a crash occured. At
|
||||||
|
this point an error occurs and the user is told to rebuild the file.
|
||||||
|
A rebuild scans the rows and rewrites the meta file. If corruption is found
|
||||||
|
in the data file then the meta file is not repaired.
|
||||||
|
|
||||||
No attempts at durability are made. You can corrupt your data. A repair
|
At some point a recovery method for such a drastic case needs to be divised.
|
||||||
method was added to repair the meta file that stores row information,
|
|
||||||
but if your data file gets corrupted I haven't solved that. I could
|
|
||||||
create a repair that would solve this, but do you want to take a
|
|
||||||
chance of loosing your data?
|
|
||||||
|
|
||||||
Locks are row level, and you will get a consistant read. Transactions
|
Locks are row level, and you will get a consistant read.
|
||||||
will be added later (they are not that hard to add at this
|
|
||||||
stage).
|
|
||||||
|
|
||||||
For performance as far as table scans go it is quite fast. I don't have
|
For performance as far as table scans go it is quite fast. I don't have
|
||||||
good numbers but locally it has out performed both Innodb and MyISAM. For
|
good numbers but locally it has out performed both Innodb and MyISAM. For
|
||||||
@@ -88,7 +90,6 @@
|
|||||||
compression but may speed up ordered searches).
|
compression but may speed up ordered searches).
|
||||||
Checkpoint the meta file to allow for faster rebuilds.
|
Checkpoint the meta file to allow for faster rebuilds.
|
||||||
Dirty open (right now the meta file is repaired if a crash occured).
|
Dirty open (right now the meta file is repaired if a crash occured).
|
||||||
Transactions.
|
|
||||||
Option to allow for dirty reads, this would lower the sync calls, which would make
|
Option to allow for dirty reads, this would lower the sync calls, which would make
|
||||||
inserts a lot faster, but would mean highly arbitrary reads.
|
inserts a lot faster, but would mean highly arbitrary reads.
|
||||||
|
|
||||||
@@ -355,6 +356,7 @@ ARCHIVE_SHARE *ha_archive::get_share(const char *table_name, TABLE *table)
|
|||||||
opposite.
|
opposite.
|
||||||
*/
|
*/
|
||||||
(void)write_meta_file(share->meta_file, share->rows_recorded, TRUE);
|
(void)write_meta_file(share->meta_file, share->rows_recorded, TRUE);
|
||||||
|
|
||||||
/*
|
/*
|
||||||
It is expensive to open and close the data files and since you can't have
|
It is expensive to open and close the data files and since you can't have
|
||||||
a gzip file that can be both read and written we keep a writer open
|
a gzip file that can be both read and written we keep a writer open
|
||||||
@@ -401,6 +403,8 @@ int ha_archive::free_share(ARCHIVE_SHARE *share)
|
|||||||
(void)write_meta_file(share->meta_file, share->rows_recorded, FALSE);
|
(void)write_meta_file(share->meta_file, share->rows_recorded, FALSE);
|
||||||
if (gzclose(share->archive_write) == Z_ERRNO)
|
if (gzclose(share->archive_write) == Z_ERRNO)
|
||||||
rc= 1;
|
rc= 1;
|
||||||
|
if (my_close(share->meta_file, MYF(0)))
|
||||||
|
rc= 1;
|
||||||
my_close(share->meta_file,MYF(0));
|
my_close(share->meta_file,MYF(0));
|
||||||
my_free((gptr) share, MYF(0));
|
my_free((gptr) share, MYF(0));
|
||||||
}
|
}
|
||||||
|
Reference in New Issue
Block a user