The GET_PARAM() function retrieves a parameter that was placed on the transaction bulletin board using the PUT_PARAM() function or with statements SAVE PROPERTY, SAVE DEFAULT PROPERTY, or SET SYNC PARAMETER. The parameter that is retrieved is specific to a catalog; each catalog has a different set of parameters.
If the parameter does not exist in the bulletin board, the function returns the VARCHAR value of the parameter or NULL.
Because get_param() is an SQL function, it can be used only in a procedure or as part of a SELECT statement.
The parameter name must be enclosed in quotation marks.
The GET_PARAM() function applies only to advanced replication configurations; it can be issued on both master and replica databases.
solidDB® system parameters
solidDB® system parameters are divided into the following categories:
Read-only system parameters
Read-only system parameters are maintained by solidDB® and can be read only by using the following syntax:
GET_PARAM(parameter_name)
The lifecycle of parameters in this category is one transaction, that is, values of these parameters is always initialized at the beginning of the transaction.
Updatable transaction-level system parameters
Users can set and update transaction-level system parameters using the following function call inside the transaction:
PUT_PARAM(parameter_name, value)
Updatable system parameters are used by solidDB® advanced replication to configure synchronization-related operations.
The lifecycle of parameters in this category is one transaction, that is, values of these parameters is always initialized at the beginning of the transaction.
Database catalog level system parameters
Database catalog level system parameters are set by using the followingsyntax:
SETSYNCPARAMETER(parameter_namevalue)
Parameters in this category are database catalog level parameters that are valid until changed or removed. They are specified as bulletin board parameters.