SQLite3 check for locked.
lazarus / 16-Databases

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chrnobel · 2012-01-16 23:48

Hi all.

Albeit SQLite3 is a single user database, it is quite usable as a
(smaller) multiuser database, if it primarily is going to be used for
reads.

However in my application I do have some writes which gives me
concurrency problems, however they should be to overcome if just
waiting a little while, as a typical transaction takes less than
100ms.

But sometimes it goes wrong if trying to read at exactly the same time
as a write is being committed, so is there some way to check the
SQLite3connection for whether the database is locked, so instead of
raising an error I just can wait eg. 100 ms, and then try again?

Tnx
Christain

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LuizAmérico · 2012-01-17 00:48

Try using sqlite3_busy_timeout  or add a busy handler (see docs in
site)

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LuizAmérico · 2012-01-17 00:49

Also you can use the new wal mode: http://www.sqlite.org/wal.html

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chrnobel · 2012-01-17 08:05

Quote from: LuizAmérico on January 17, 2012, 01:48:36 amTry using
sqlite3_busy_timeoutIs this a FPC property?
Quote  (see docs in site)Which docs?

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Lacak2 · 2012-01-19 05:20

Quote from: chrnobel on January 17, 2012, 09:05:15 amQuote from:
LuizAmérico on January 17, 2012, 01:48:36 amTry using
sqlite3_busy_timeoutIs this a FPC property?
No it is SQLite3 API function:
http://www.sqlite.org/c3ref/busy_timeout.html

Quote from: chrnobel on January 17, 2012, 09:05:15 amQuote  (see docs
in site)Which docs?
http://www.sqlite.org/c3ref/intro.html