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Overview
Comment:Improvements to VACUUM documentation - describe more clearly when another transaction might block a vacuum.
Timelines: family | ancestors | descendants | both | branch-3.27
Files: files | file ages | folders
SHA3-256: 0f897a0268b33f51f38356aafeda60ff0ff6a31f1da9748bc5a13961b536bc1a
User & Date: drh 2019-04-01 14:44:28
Context
2019-04-08
18:08
Fix a minor error in the datatype documentation. Leaf check-in: 87bef3d123 user: drh tags: branch-3.27
2019-04-01
14:45
Merge changes from the 3.27 branch. check-in: 50513b6f28 user: drh tags: trunk
14:44
Improvements to VACUUM documentation - describe more clearly when another transaction might block a vacuum. check-in: 0f897a0268 user: drh tags: branch-3.27
2019-03-25
14:32
Import typo fixes from trunk. check-in: 6f80f0890f user: drh tags: branch-3.27
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Changes to pages/lang.in.

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named on the INTO clause in place of the temporary database and omits the
step of copying the vacuumed database back over top of the original database.

<p>^The VACUUM command may change the [ROWID | ROWIDs] of entries in any
tables that do not have an explicit [INTEGER PRIMARY KEY].
</p>

<p>^A VACUUM will fail if there is an open transaction, or if there are one or
more active SQL statements when it is run.






<p>^(An alternative to using the VACUUM command to
reclaim space after data has been deleted is auto-vacuum mode, enabled using
the [auto_vacuum] pragma.)^ ^When [auto_vacuum] is enabled for a database
free pages may be reclaimed after deleting data, causing the file to shrink,
without rebuilding the entire database using VACUUM.  ^However, using
[auto_vacuum] can lead to extra database file fragmentation.  ^And [auto_vacuum]







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named on the INTO clause in place of the temporary database and omits the
step of copying the vacuumed database back over top of the original database.

<p>^The VACUUM command may change the [ROWID | ROWIDs] of entries in any
tables that do not have an explicit [INTEGER PRIMARY KEY].
</p>

<p>^A VACUUM will fail if there is an open transaction on the database
connection that is attempting to run the VACUUM.  ^Unfinalized SQL
statements typically hold a read transaction open, so the VACUUM
might fail if there are unfinalized SQL statements on the same connection.
^VACUUM (but not VACUUM INTO) is a write operation and so if another
database connection is holding a lock that prevents writes, then
the VACUUM will fail.

<p>^(An alternative to using the VACUUM command to
reclaim space after data has been deleted is auto-vacuum mode, enabled using
the [auto_vacuum] pragma.)^ ^When [auto_vacuum] is enabled for a database
free pages may be reclaimed after deleting data, causing the file to shrink,
without rebuilding the entire database using VACUUM.  ^However, using
[auto_vacuum] can lead to extra database file fragmentation.  ^And [auto_vacuum]