gpdbguru

Err: Invalid memory alloc request size Orca issue in GP6.11.0  Due to ORCA memory error, it caused user function failure alone with segments going down. DTXRollbackAndReleaseCurrentSubTransaction dispatch failed causing DTM error and makes segments to go down. Orca error is causing a memory to not be properly released from the database and potentially impacting other concurrent processes that requrie reserved memory. Failure with union clauses and the metrics collector causing 'Invalid Memory Alloc' have been fixed in GP6.12.0.

Q1. When Batch insert is running via JDBC, those are processed as individual inserts in DB. Is this expected behavior in Greenplum? Answer: YES, This is an expected behavior, this is done to ensure atomicity.  Q2. Does individual insert statement performance differ for AO row based vs AO columnar tables, and how?  Answer: Row base tables are more suitable for inserts / update than columnar as for as one insert only file accessed. In columnar table each column has a separate file, so it will be a bit slower than row base table insert or any DML operation as each.  Here in this case, when an insert is happening on a separate file will be created for each column insert and in Greenplum each column is a separate physical file on every segment. Columnar is actually good for selects sorts of operations. Row base tables provide much better performance. Q3. Why don't I see any DDL queries in queries_history table? Answer: Yes, DDL queries are not captured in queries...