The solidDB transaction log reader (Logreader) is a solution that makes it possible to read log records from the solidDB transaction log one transaction at a time. For example, by using the Logreader interface, you can write an application that listens to and displays log traffic in the solidDB server.

Logreader is based on a read-only system table called SYS_LOG, where each row corresponds to a single log entry. The SYS_LOG table is a virtual table; when Logreader receives an SQL request for the SYS_LOG table, the appropriate result set is generated dynamically from the internal log structures. Each log read can start from a different log record.

For each entry in the transaction log, the SYS_LOG table contains data that identifies the log record, the type of transaction and statement executed, as well as the row with the changed data.

The SYS_LOG table can be accessed with ODBC and JDBC drivers by using SQL statements. For example, an application could be written to read the solidDB transaction log and extract records that pertain to SQL DML statements. The application could then reconstruct the statements into plain text SQL strings and print them to a desired type of output.

Applications can read the SYS_LOG table both locally and remotely. Several applications can read the SYS_LOG table concurrently without interference.

A sample application that demonstrates the use of the Logreader interface is included in the solidDB package, see Logreader sample.

For a detailed description of the SYS_LOG table, see SYS_LOG.