Skip to main content

What if i drop all the projections on a table

  • August 23, 2013
  • 2 replies
  • 20 views

Ravi_Vijay
Forum|alt.badge.img
Hi All, Maybe a naive question. What if I drop all the projections (including the super projections) on a table ? Would I be losing data ? On a side note how do I identify if a projection is a super projection from the entries in the projections table. The reason I ask all this is while trying the function move_partitions_to_table I get the error that some of the projections are unsegmented. On checking the schema, all the super projections (covering all the columns) seem to be having the unsegmented option (Most of them are confined to a single node , just one is using all nodes which implies replication). I want to delete those unsegmented projections and create them with the segmented option, however I fear that I might be deleting some data permanently. Thanks, Ravi.

2 replies

Sharon_Cutter
Forum|alt.badge.img
  • Participating Frequently
  • August 23, 2013
No need to worry about dropping the last super projection. Vertica won't let you. dbadmin=> drop projection t1_super; ROLLBACK 4122: No up-to-date super projection left on the anchor table of projection t1_super HINT: Use DROP TABLE ... CASCADE to drop the anchor table and its last projection, or create a replacement super projection instead The PROJECTIONS table has a is_super_projection column. --Sharon

matthewcornell
Forum|alt.badge.img+1
  • Participating Frequently
  • February 11, 2014
Question: How do I "revert" back to the original superprojections?