On Sun, 02 Oct 2011 21:20:27 +0800, ?????? <[email protected]>
wrote:
> thank you very much for replying me. my application is really
> very slow when insert data, and i have tried translation.
I guess you mean transaction, not translation?
> but it does not increase speed. so what can i do?
Did you execute many INSERT statements in a
BEGIN TRANSACTION; / COMMIT TRANSACTION; pair,
or just one INSERT statement?
To tell more we need more information about your problem, like:
- the database schema
- the code you use to execute INSERT statements
- some information about your hardware environment
- the speed you experience
- the speed you would need
A few general speed improvemnt hints:
1) Put the database in a very fast filesystem,
like Solaris tempfs (memory) or a RAMdisk.
If that is not possible, build an in-memory database
and transfer it to a disk file using the backup API.
2) PRAGMA page_size={the optimal database page size
for your filesystem and average row size};
If you want store BLOBs, use a larger page_size,
and put the blob columns in a separate table using
the same primary key and join with the primary table
if you need the blob in the resultset.
3) PRAGMA cache_size={many pages};
PRAGMA default_cache_size={many pages};
4) PRAGMA jounal_mode=OFF; -- note: use with caution.
5) PRAGMA synchronous=OFF;
6) PRAGMA temp_store=MEMORY;
7) PRAGMA foreign_keys=OFF;
9) Sort INSERT statements in the order of the key of the most
complicated index.
10) Postpone CREATE INDEX statements until after all tables are
loaded.
Once the database is complete:
11) VACUUM;
12) ANALYZE;
13) when possible use INTEGER primary keys.
Probably there are a few more.
See also:
http://www.sqlite.org/pragma.html
--
( Kees Nuyt
)
c[_]
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