The SQL statement is so easy.
the table create statement as following:
CREATE TABLE poiTable (poiId INTEGER NOT NULL, versionId INTEGER NOT NULL,
regionId INTEGER , postalCode TEXT , phone TEXT , attrBitMask INTEGER ,
attributeBlob BLOB , primary key (poiId));
So the poiId is equal to the rowid.
such as : select * from poiTable where poiId = ... ;
And execute the sql by sqlite3_prepare_v2?sqlite3_step?
how could I improve the performance?
At 2015-12-21 17:15:56, "???" <2004wqg2008 at 163.com> wrote:
>What Simon said is very helpful for me. Thank you very much.
>I only want to improve the speed of reading data from data base. Do not do
>insert?update and so on.
>
>I will try the following suggustion.
>PRAGMA synchronous = OFF
>
>Best regards
>
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>At 2015-12-21 17:03:13, "Simon Slavin" <slavins at bigfraud.org> wrote:
>>
>>On 21 Dec 2015, at 6:19am, ??? <2004wqg2008 at 163.com> wrote:
>>
>>> The meaning of "how to use sqlite_table" is that I guess the sqlite_table
>>> may have contained some information which could help to improve speed.
>>> I am not meaning to modify the data structure of sqlite_master.
>>
>>There is nothing you can do with sqlite_table to improve speed. Unless you
>>have a very unusual setup there is nothing you can do with compilation
>>options to improve speed.
>>
>>Since you say you are not using multi-threading or multi-process, you might
>>like to read the documentation for
>>
>>PRAGMA synchronous = OFF
>>
>>This might increase speed for you. However it also means that if your
>>computer loses power or crashes while the database is open, you will lose
>>more new data.
>>
>><https://www.sqlite.org/pragma.html>
>>
>>However a big increase in speed comes from correct use of indexes. If you
>>have any SQL commands which include WHERE or ORDER BY, then these will
>>execute faster if you have an ideal index on the table they use. This can
>>affect INSERT and UPDATE and DELETE FROM commands. If you want help with
>>this you must post your SQL commands here.
>>
>>Another big increase in speed can come from correctly using transactions.
>>When you are making changes to your database it is finishing the transaction
>>with END or COMMIT which takes most of the time. So if you have many INSERT
>>commands then
>>
>>INSERT ...
>>INSERT ...
>>INSERT ...
>>
>>is slow but
>>
>>BEGIN
>>INSERT ...
>>INSERT ...
>>INSERT ...
>>COMMIT
>>
>>can be much faster. This can affect INSERT and UPDATE and DELETE commands.
>>
>>Simon.
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