[TRAFODION-2946] LOB : Locking/transaction support needed for LOB files for DDL and IUD operations

• Type: New Feature
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: any
• Component/s: dtm, sql-general
• Assignee: Sandhya Sundaresan
• Reporter: Sandhya Sundaresan
• Created: 01/Feb/18 18:36
• Updated: 24/Jan/19 06:34

Description

Trafodion DTM needs to recognize LOB HDFS data files that contain the actual critical data for a LOB column and treat them as part of the Trafodion object that contains the LOB column. The Trafodion table itself contains the LOB handle that can be used to derive the LOB data file name/location. 

DDL operations performed on LOB tables today only work on the Trafodion table. The dependent HDFS data files are not treated as part of the DDL transaction. ANy parallel operations or errors during create/drop will leave the table in an inconsistent state. 

 

DML operations on any LOB table only work on the LOB table and it's dependent descriptor tables that are also Trafodion tables (contain offset/length information in the HDFS data file  for each LOB column). But the HDFS data file operation is not covered as part of the  transaction. So any IUD error will leave the LOB table in  an inconsistent state . 

Issue Links

• relates to: TRAFODION-3263 Disable LOB locking and refactor order of LOB iud expression evaluation
• links to: GitHub Pull Request #1586