LVARCHAR(m) data type

Use the LVARCHAR data type to create a column for storing variable-length character strings whose upper limit (m) can be up to 32,739 bytes.

This limit is much greater than the VARCHAR data type, which is used for character strings that are no longer than 255 bytes.

The LVARCHAR data type is implemented as a built-in opaque data type. You can access LVARCHAR columns in remote tables by using distributed queries across databases of the same or different HCL OneDB™ instances.

By default, the database server interprets quoted strings as LVARCHAR types. It also uses LVARCHAR for input and output casts for opaque data types.

The LVARCHAR data type stores opaque data types in the string (external) format. Each opaque type has an input support function and cast, which convert it from LVARCHAR to a form that database servers can manipulate. Each opaque type also has an output support function and cast, which convert it from its internal representation to LVARCHAR.

Important: When LVARCHAR is declared (with no size specification) as the data type of a column in a database table, the default maximum size is 2 KB (2048 bytes), but you can specify an explicit maximum length of up to 32,739 bytes. When LVARCHAR is used in I/O operations on an opaque data type, however, the maximum size is limited only by the operating system.

You cannot use the MEDIUM or HIGH options of the UPDATE STATISTICS statement to calculate distribution statistics on LVARCHAR columns.

Size specifications in LVARCHAR data type declarations can be affected by the SQL_LOGICAL_CHAR feature that is described in the section Logical Character Semantics in Character Type Declarations.

For more information about LVARCHAR, see the HCL OneDB User-Defined Routines and Data Types Developer's Guide.