gianm commented on a change in pull request #6094: Introduce SystemSchema tables (#5989) URL: https://github.com/apache/incubator-druid/pull/6094#discussion_r209744738
########## File path: docs/content/querying/sql.md ########## @@ -481,6 +485,77 @@ SELECT * FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA = 'druid' AND TABLE_ |COLLATION_NAME|| |JDBC_TYPE|Type code from java.sql.Types (Druid extension)| +## SYSTEM SCHEMA + +SYSTEM_TABLES provide visibility into the druid segments, servers and tasks. +For example to retrieve all segments for datasource "wikipedia", use the query: +```sql +select * from SYS.SEGMENTS where DATASOURCE='wikipedia'; +``` + +### SEGMENTS table +Segments tables provides details on all the segments, both published and served(but not published). + + +|Column|Notes| +|------|-----| +|SEGMENT_ID|| +|DATASOURCE|| +|START|| +|END|| +|IS_PUBLISHED|segment in metadata store| +|IS_AVAILABLE|segment is being served| +|IS_REALTIME|segment served on a realtime server| +|PAYLOAD|jsonified datasegment payload| + +### SERVERS table + + +|Column|Notes| +|------|-----| +|SERVER|| +|SERVER_TYPE|| +|TIER|| +|CURRENT_SIZE|| +|MAX_SIZE|| + +To retrieve all servers information, use the query +```sql +select * from SYS.SERVERS; +``` + +### SEGMENTSERVERS table + +SEGMENTSERVERS is used to join SEGMENTS with SERVERS table + +|Column|Notes| +|------|-----| +|SERVER|| +|SEGMENT_ID|| + +### TASKS table + +TASKS table provides tasks info from overlord. + +|Column|Notes| +|------|-----| +|TASK_ID|| Review comment: These should all have comments too. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@druid.apache.org For additional commands, e-mail: commits-h...@druid.apache.org
