Pointer Page. Each table has one or more of these and this page type keeps track of all the pages that make up the table. Pointer pages are owned by one and only one table, there is no sharing allowed. Each Description ---------------------------------------------------------------------------------- 000a0014 fc ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff tip_transactions[] 000a0024 ff ff ff ff ff ff ff ff Description ---------------------------------------------------------------------------------- 000a0014 fc ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff tip_transactions[] 000a0024 ff ff ff ff ff ff ff ff

expressions like “if ( MyField = NULL ) then…”, and so on. However, as a general rule you should not make use of these new possibilities! In almost every thinkable situation, such use of NULL literals is if exactly one row in the subquery meets the search condition. By analogy with EXISTS this would make you expect that SINGULAR too will only ever return true or false. After all, a result set Chapter column with (1, 1, NULL) returns false. Notice that only the insertion order is different here! To make matters worse, all versions prior to 2.0 sometimes return NULL for NOT SINGULAR where false or true

IMPORTANT A long-standing, legacy loophole in the handling of DPB parameters enabled ordinary users to make con- nection settings that could lead to database corruptions or give them access to SYSDBA-only operations will not work as expected. If the Windows installer program finds a value for %FIREBIRD% it will make that path the default location that it offers, instead of c:\Program Files\Firebird\Firebird_2_1 old server's version of gbak and then restore it using the Firebird 2.0 gbak. Important You must make sure that you restore the security database to have a page size of at least 4 Kb. The new security2

дополнительными фильтрами, такими, как эти: SELECT AU.MAKE, AU.MODEL, AU.WEIGHT, AU.PRICE, AU.IN_STOCK FROM AUTOMOBILES AU WHERE (AU.MAKE = :MAKE OR :MAKE IS NULL) AND (AU.MODEL = :MODEL OR :MODEL IS NULL) Идея состоит в том, что конечный пользователь может дополнительно ввести варианты для параметров :make, :model и :maxprice. Там, где сделан выбор, должен быть применен соответствующий фильтр. Везде такие как :make, :model и :maxprice. существует только на уровне приложений. Прежде чем запрос передается серверу Firebird для подготовки, он должен быть преобразован в такую форму: SELECT AU.MAKE, AU.MODEL

may distribute such modified versions, but if you do so, you must document your modifications and make them publicly available, at no cost, under the same license as the original code. • You may include install.sh. In some cases, the Release Notes or packed Readmes may instruct you to edit the scripts and make some manual adjustments. 3.3. Installing multiple servers Firebird allows the operation of multiple installation packages start up the Firebird server as one of the final steps during installation, and also make sure that Firebird is started at every reboot. After being launched, the Firebird server should be

Firebird 2.0.2 was recalled due to a regression; if you use it, upgrade to 2.0.3 or higher ASAP and make sure to read your new version's Release Notes. • If you want to rely on Linux forced writes to work may distribute such modified versions, but if you do so, you must document your modifications and make them publicly available, at no cost, under the same license as the original code. • You may include This leads to errors when it tries to overwrite existing DLLs and executables. So, in the above case, make sure to uninstall any existing Firebid server before attempt- ing to install the new one. This bug

version of the command will exit with a error code of zero.  This method of calling gbak will make a backup of the database. If your database is large, this can take some time to complete and the specify one of -c[create database], -rep[lace_database] or -r[ecreate_database] in order to make your intentions clear. The database will be restored to whatever file name is specified as the second 3. Backup Mode Before you consider using other tools to take a backup of your Firebird database, make sure that you know what the tools do and how a running database will be affected by them. For example

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 491 8.12.1. MAKE_DBKEY(). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . precision is rare and is not supported by all drivers and access components. The best assumption to make from all this is that, although Firebird stores TIME and the TIMESTAMP time-part values as the number BOOLEAN data type also supports the truth value UNKNOWN as the null value. The specification does not make a distinction between the NULL value of this data type, and the truth value UNKNOWN that is the result

Deci-milliseconds precision is rare and is not currently stored in columns or variables. The best assumption to make from all this is that, although Firebird stores TIME and the TIMESTAMP time-part values as the number Firebird DBMS is a departure from the traditional relational model. Supporting arrays in the DBMS could make it easier to solve some data-processing tasks involving large sets of similar data. Arrays in Firebird course. A domain provides the means to encapsulate an existing data type with a set of attributes and make this “capsule” available for multiple usage across the whole database. If several tables need columns

you… • are not familiar with the concept of generators; • have questions on using them; • want to make an Integer column behave like an “AutoInc” field as found in other RDBMSs; • are looking for examples other concurrent transactions may have changed the value in between. For the same reason it doesn’t make sense to get the current value with GEN_ID(mygen,0) and then increment the value on the client side values, and a well-thought-out mechanism to Chapter 4. Using generators to create unique row IDs 12 make this work safely in multi-user/multi-transaction environments, JUST DON’T DO IT! 4.4. Generators