All, the VACUUM in PostgreSQL removes delete-marked records from the database.
In InnoDB, the VACUUM is called the purge. In InnoDB purge happens automatically in the background, the user does not need to explicitly run VACUUM, like in PostgreSQL. Also in Oracle purge is automatic. The way to compact, reorganize, or optimize, an InnoDB table is to run ALTER TABLE tablename TYPE=InnoDB; It rebuilds the table. The command ANALYZE TABLE tablename; in InnoDB updates the table statistics for the SQL optimizer. InnoDB constantly updates the row count estimate, but only updates the index cardinality estimates for join optimization at a mysqld startup, or when ANALYZE TABLE is called. This is similar to MyISAM. But remember that in InnoDB the estimates are not precise, but based on 8 random dives into the index trees. Best regards, Heikki Innobase Oy http://www.innodb.com InnoDB - transactions, row level locking, and foreign keys for MySQL InnoDB Hot Backup - hot backup tool for InnoDB which also backs up MyISAM tables .................... From: Chris Nolan ([EMAIL PROTECTED]) Subject: Re: Optimizing table (so-called VACUUM on postgreSQL) and InnoDB View: Complete Thread (3 articles) Original Format Newsgroups: mailing.database.myodbc Date: 2003-10-24 00:35:58 PST VACUUM is basically a workalike for: ALTER TABLE <table_name> TYPE=3DInnoDB; There are various types of VACUUM commands as well. VACUUM FULL basically locks the table and shrinks the on-disk table space. The normal "VACUUM" (normal since 7.2 I think), does not lock the table (similar to REORGANISE in some other databases, while REORGANISE in some databases like SQLBase REORGANISE locks everything) but does a basic defrag. Hope this helps! Regards, Chris On Fri, 24 Oct 2003 05:23 pm, Jeremy Zawodny wrote: > On Thu, Oct 16, 2003 at 05:13:58PM -0300, Leonardo Rodrigues wrote: > > Hello all, > > > > The referencial integrity control don=B4t apply to a simple table, do > > it? > > What's a "simple" table? > > > My DB is growing, and growing, and I=B4m very concerned about my host > > limitions of disk usage. So... > > You should be! > > > Another question: postgreeSQL has a SQL command called VACUUM, which > > optimize and reduce the table=B4s used space disk. I discover for mySQL= the > > commands "OPTIMIZE TABLE" and "ANALYZE TABLE", but both don=B4t run on > > InnoDB. > > ANALYZE table runs on InnoDB. > > > My question are: are these commands similar to VACUUM? What=B4s the > > difference? How can I run on InnoDB? > > I don't know much about PostgreSQL, so I'm not sure. If you describe > what VACUUM does, I may be able to help explain how to do the same > thing with MySQL. > > Jeremy > -- > Jeremy D. Zawodny | Perl, Web, MySQL, Linux Magazine, Yahoo! > <[EMAIL PROTECTED]> | http://jeremy.zawodny.com/ > > MySQL 4.0.15-Yahoo-SMP: up 40 days, processed 1,530,867,850 queries > (439/sec. avg) -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
