Derby provides a set of
system table expressions which you can use to obtain diagnostic information
about the state of the database and about the database sessions.
There are two types of diagnostic table expressions in
Derby:
- Diagnostic tables
- Tables that are like any other table in
Derby. You can specify the
diagnostic table name anywhere a normal table name is allowed.
- Diagnostic table functions
- Functions that are like any other function in
Derby. Diagnostic table
functions can accept zero or more arguments, depending on the table function
that you use. You must use the SQL-defined table function syntax to access these
functions.
The following table shows the types and names of the diagnostic table
expressions in Derby.
Table 1. System diagnostic table expressions provided by
Derby
| Diagnostic Table Expression |
Type of Expression |
| SYSCS_DIAG.CONTAINED_ROLES |
Table function |
| SYSCS_DIAG.ERROR_LOG_READER |
Table function |
| SYSCS_DIAG.ERROR_MESSAGES |
Table |
| SYSCS_DIAG.LOCK_TABLE |
Table |
| SYSCS_DIAG.SPACE_TABLE |
Table function |
| SYSCS_DIAG.STATEMENT_CACHE |
Table |
| SYSCS_DIAG.STATEMENT_DURATION |
Table function |
| SYSCS_DIAG.TRANSACTION_TABLE |
Table |
Restriction: If you reference a diagnostic table in a DDL statement
or a compression procedure,
Derby returns an
exception.