Available with Production Mapping license.
Enterprise geodatabases use log file tables to maintain lists of selected records. Records are written to log file tables for later use by the application whenever a selection of a specific size is made, a reconciliation or post on a versioned database is performed, or a disconnected editing checkout is done in a client application. The log file tables store the ObjectIDs of the selected features so they can be redisplayed. This allows for faster analysis and processing of information.
In ArcGIS, by default, log file tables are used if the selection set contains 100 or more records. This selection threshold of 100 features is set in the registry. It can be changed; however, Esri does not recommend you do so. There is no proven performance reason for changing it, and doing so could cause performance problems.
Geodatabases in SQL Server use session-based log files created in the temporary database (tempdb) by default. This is the recommended setting and should be sufficient in most cases. However, if you want to change settings, see Alter log file table settings.
When working with results in the workspace, it is best to understand the log file table configuration options so you can choose the right option for your database needs. There are four different geodatabase log file options: shared, session-based, stand-alone, and pools of session-based or stand-alone log files.
Common configuration options
For SQL Server, the default log file configuration is session-based log files created in the temporary database (tempdb). In most cases, the default geodatabase log file table configuration for your database management system (DBMS) should be sufficient and is the recommended setting. Another common option is the shared log files. You would only use shared log files if you do not want to create tables in the tempdb, you have a large number of concurrent sessions, and each session connects using an individual DBMS account. Either configuration option is acceptable for the workspace, but if you choose to store the log tables in the user schema (shared log files), instead of the tempdb (session-based), be sure to give CREATE TABLE privileges to each user accessing the tables.
Settings to control storage
Log file options are set using specific parameters in the SDE_server_config and SDE_dbtune tables.
For session-based log files, the DBTUNE SESSION_TEMP_TABLE parameter must be set to 1 (true) to allow the session-based log file table to be created in tempdb. For shared log files, changing the SESSION_TEMP_TABLE parameter to 0 (false) will create the SDE_LOGFILES, SDE_LOGFILE_DATA, and SDE_SESSION<SDE_ID> tables in the connecting user's schema; hence, the user requires CREATE TABLE permission.
Parameters in these tables are altered using the sdeconfig and sdedbtune commands, respectively. In SQL Server, the table created in tempdb is in the format ##SDE_SESSION<SDE_ID>. This table is truncated when the connecting application deletes its log files, and the table is dropped when the session disconnects. When using the default setting, users do not require CREATE TABLE permission in the database for the session table to be created in tempdb.