Re: Table vs. row level locks confusion - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Table vs. row level locks confusion
Date
Msg-id 26359.999615668@sss.pgh.pa.us
Whole thread Raw
In response to Table vs. row level locks confusion  (Peter Eisentraut <peter_e@gmx.net>)
List pgsql-hackers
Peter Eisentraut <peter_e@gmx.net> writes:
> The following section
> http://www.ca.postgresql.org/devel-corner/docs/postgres/locking-tables.html
> titled "Locking and Tables", has two subsections, "Table-level locks" and
> "Row-level locks".  Under table-level locks we find lock names such as
> RowShareLock and RowExclusiveLock -- are those table-level locks?

Yes, despite the names.  (The various lock-type names are pretty
horrible IMHO, but they are claimed to be Oracle-compatible.)
Anything you do with a LOCK command is a table-level lock.

> Under row-level locks we find no specific lock names mentioned.

The only row-level locking mechanism available to users is
to UPDATE, DELETE, or SELECT FOR UPDATE a particular row.
All rows affected by such a command are locked against other
such commands (but not against plain SELECT).
        regards, tom lane


pgsql-hackers by date:

Previous
From: Tom Lane
Date:
Subject: Re: [BUGS] Build problem with CVS version
Next
From: "Joe Conway"
Date:
Subject: Re: Bytea/Base64 encoders for libpq - interested?