Updating The Time Zone Database

SQL Language StructureCommon Language Elements

Updating the Time Zone Database

Time zones are often changed: of course, when it happens, it is desirable to update the time zone database as soon as possible.

Firebird stores WITH TIME ZONE values translated to UTC time.Suppose a value is created with one time zone database, and a later update of that database changes the information in the range of our stored value.When that value is read, it will be returned as different to the value that was stored initially.

Firebird uses the IANA time zone database through the ICU library.The ICU library included in the Firebird kit (Windows), or installed in a POSIX operating system, can sometimes have an outdated time zone database.

An updated database can be found on this page on the FirebirdSQL GitHub.Filename le.zip stands for little-endian and is the necessary file for most computer architectures (Intel/AMD compatible x86 or x64), while be.zip stands for big-endian architectures and is necessary mostly for RISC computer architectures.The content of the zip file must be extracted in the /tzdata sub-directory of the Firebird installation, overwriting existing *.res files belonging to the database.

Note	`/tzdata` is the default directory where Firebird looks for the time zone database.It can be overridden with the `ICU_TIMEZONE_FILES_DIR` environment variable.

Character Data Types

For working with character data, Firebird has the fixed-length CHAR and the variable-length VARCHAR data types.The maximum size of text data stored in these data types is 32,767 bytes for CHAR and 32,765 bytes for VARCHAR.The maximum number of characters that will fit within these limits depends on the character set used for the data under consideration.The collation does not affect this maximum, although it may affect the maximum size of any index that involves the column.

If no character set is explicitly specified when defining a character object, the default character set of the database — at time of defining the object — will be used.If the database does not have a default character set defined, the object gets the character set NONE.