Добавил:
Upload Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз: Предмет: Файл:
Скачиваний:
36
Добавлен:
18.03.2015
Размер:
684.09 Кб
Скачать

Global Improvements in Firebird 2.1

Note

A faintly possible side-effect is that, if isc_dsql_execute should happen to fail with a certain exception, this exception is returned to the client in the response to the API call that was actually responsible; i.e., instead of being returned by isc_dsql_execute it would be returned by isc_dsql_fetch, isc_dsql_info, or whichever API call actually dispatched the op_execute call.

In most cases, the side-effect would be transparent: it might show up in a case where some error occurred with default values for PSQL parameters or variables and would be noticed as an exception array where the exceptions were delivered in an unusual sequence.

The changes work with either TCP/IP or NetBEUI. They are backward-compatible, so existing client code will not be broken. However, when you are using a driver layer that implements its own interpretation of the remote protocol—such as the Jaybird JDBC and the FirebirdClient .NET drivers—your existing code will not enable the enhancements unless you usedrivers are updated.

API Changes

XSQLVAR

A. dos Santos Fernandes

The identifier of the connection character set or, when the connection character set is NONE, the BLOB character set, is now passed in the XSQLVAR::sqlscale item of text BLOBs.

Optimization

Optimization for Multiple Index Scans

V. Khorsun

Feature request CORE-1069

An optimization was done for index scanning when more than one index is to be scanned with AND conjunctions.

Optimize sparse bitmap operations

V. Khorsun

Feature request CORE-1070

Optimization was done for sparse bitmap operations (set, test and clear) when values are mostly consecutive.

23

Соседние файлы в папке doc