Function strings contain instructions for executing a function in a database.
These instructions may differ according to database. For example, a non-Sybase database may require different instructions and have different function strings than an Adaptive Server database.
Functions strings come in two formats: language and (remote procedure call) RPC. A language-format function string contains a command, such as a SQL statement, that the data server parses. An RPC-format function string contains a remote procedure call that executes a registered procedure in an Open Server™ gateway application or in an Adaptive Server database. Both function-string formats can contain variables that can be replaced with data values. The format used by a function string is determined by the type of data server and how you want Replication Server to interact with it. You can alter output templates to customize function strings.
Function strings are grouped into function-string classes. Each database connection must be assigned a function-string class according to the type of replicate database. Replication Server provides function-string classes that generate default function strings for all actively supported data servers.
When you set up a replication system or add databases to the system, anticipate your function-string requirements and decide how you will use function-string classes and whether you need to customize function strings.