In last time I observed in HANA system worrying growth a table replicated by SDI which size is now above 100GB. The table at source system is only 2.8GB. It’s worth noting:
- DB source is MSSQL;
- three of the columns are NCLOB datatype;
- We reduced the size of the table by implementing note: 2950474 but the size is growing again.
Useful information You can receive from below reports.
Check the output of below query :
CALL CHECK_TABLE_CONSISTENCY('CHECK_HYBRID_LOB_OVERHEAD', '', '');
Also run the below reports from the attached SQL in the Note 1969700 :
- Overview of disk LOB files;
As I earlier mentioned we reduced the size of the table by implementing note: 2950474 – was executed the repair job: REPAIR_HYBRID_LOB_OVERHEAD. Unfortunately the size is grew again.
Finally it turned out this is a known issue that table consistency check methods CHECK_HYBRID_LOB_OVERHEAD and REPAIR_HYBRID_LOB_OVERHEAD do not correctly report and repair disk level fragmentation of packed LOB containers. This causes affected packed LOB columns to consume more space on disk than necessary.
- SAP HANA 2:
- Revisions <= 048.03 (SPS04)
- Revisions <= 054.00 (SPS05)
Belongs apply one of the following SAP HANA Revisions:
- SAP HANA 2:
- Revisions >= 048.04 (SPS04)
- Revisions >= 055.00 (SPS05)
- or higher
Refer more details in the attached Note 3012162 – Table Consistency Check CHECK_HYBRID_LOB_OVERHEAD and REPAIR_HYBRID_LOB_OVERHEAD Fail to Check all Packed LOB Containers.