SQLite 3.3.0 Alpha

(更新日: 2006/01/13)

SQLite 3.3は結構変わりますね。
Alphaなのでデフォルトの仕様は変わるかもしれませんが3.3は3.x系列のファイルは読めるが、3.3より以前のバージョンのSQLiteでは読めない、という点には注意が必要ですね。

* CHECK constraints are now enforced.

* The IF [NOT] EXISTS syntax of MySQL is now recognized on
CREATE/DROP TABLE/INDEX statements.

* DESC indices really are descending now. The DESC keyword
on index definitions used to be ignored.

* The database file format has changed slightly to more
compactly represent boolean values and to support DESC
indices. Version 3.3.0 will read and write all prior
version 3 databases. But new databases created by
version 3.3.0 will not be readable by older versions
of SQLite. If this is a problem for your application,
compile SQLite using

-DSQLITE_DEFAULT_FILE_FORMAT=1

and then version 3.3.0 will create new databases in
the legacy format understood by all prior versions of
SQLite. DESC indices only work in the new format.

* SQLite now distinguishes between REAL and INTEGER columns
and attempts to make appropriate conversions.

* The OS-interface layer has been modified for greater
flexibility and control of custom ports and implementations.

* SQLite now responses better to out-of-memory errors. The
library will recover and reset itself automatically. There
is no longer a need to call sqlite3_global_recover(). The
new sqlite3_enable_memory_management() API can be used to put
SQLite into a mode where it will automatically try to reduce
its database cache size when it comes under memory pressure.

* The database cache and parsed schema information can now
optionally be shared between two or more database connections.
This can be used to reduce I/O and to improve concurrency.
On a database using a shared cache, you can specify
READ UNCOMMITTED isolation as an option (the default is
SERIALIZABLE). With READ UNCOMMITTED, a reader will not
block or be blocked by a writer and you will never get
an SQLITE_BUSY error on a read.

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