One use of this diagnostic table function is to determine the active
transactions and the SQL statements in those transactions at a given point in
time. For example, if a deadlock or lock timeout occurred, you can find the
timestamp (timestampConstant) in the error log.
For a database for which authentication and SQL authorization are both
enabled, only the
database owner can
access this diagnostic table function. See "Configuring user authentication"
and "Configuring user authorization" in the
for more information.
To access the SYSCS_DIAG.ERROR_LOG_READER diagnostic table function, you must
use the SQL table function syntax.
For example:SELECT *
FROM TABLE (SYSCS_DIAG.ERROR_LOG_READER())
AS T1
where T1 is a user-specified table name that is any valid identifier.
You can specify a log file name as an optional argument to the
SYSCS_DIAG.ERROR_LOG_READER diagnostic table function. When you specify a log
file name, the file name must be an expression whose data type maps to a Java
string.
For example:SELECT *
FROM TABLE (SYSCS_DIAG.ERROR_LOG_READER('myderbyerrors.log'))
AS T1
By default,
log files contain only
boot, shutdown, and error messages. See the
derby.stream.error.logSeverityLevel
property and the
derby.language.logStatementText
property for instructions on how to print more information to
log files. You can then
query that information by using the SYSCS_DIAG.ERROR_LOG_READER diagnostic table
function.
The returned table has the columns shown in the following table.
Columns returned by the SYSCS_DIAG.ERROR_LOG_READER table function
For the columns returned by the SYSCS_DIAG.ERROR_LOG_READER table function, this table provides its data type, its length in bytes, whether it is nullable, and a description of its contents.
Column Name
Type
Length
Nullable
Contents
TS
VARCHAR
26
false
The timestamp of the statement.
THREADID
VARCHAR
40
false
The thread name.
XID
VARCHAR
15
false
The transaction ID.
LCCID
VARCHAR
15
false
The connection ID.
DATABASE
VARCHAR
128
false
The database name.
DRDAID
VARCHAR
50
true
The DRDA ID for network server session.
LOGTEXT
LONG VARCHAR
32,700
false
The text of the statement or commit or rollback.