Locking tables/projections while creating design
Hello,
I have a question about locking tables/queries.
1. Does Vertica lock some tables or projections during process of designing new projections (programatically or with DBDesigner in Admintools)? Here I mean the tables/projections which are involved in new design. I have a suspicion that during the proces of designing the original tables/projections must be in consistent state, so the content of tables/projection is during the design the same all the time (it means that the tables/projections are read-only). The problem is that it isn't possible to write to the database during the time of designing.
2. Is there any way to observe it in log files? I went through vertica.log but there was nothing about locking tables/projections.
3. Is there any way to get round the locking? I would like to work normally (write, update) with database also during the process of designing.
I hope that the questions are clear. If not, I specify it more.
Thank you for your advices.
Comments
Hi,
if you are craeting new projections does projections are NO "up_to_date" ( check in the projection table) and they were not able to answer queries. So there is not locking.
if you want to look at teh locks there is a system table lock_usage that provide details of the sessions locks.
Hope this helps.
Eugenia
Hi,
thank you for your post. I have these questions?
1. if I understand the designing process right, so the designer sets "is_up_to_date" to false in all projections (from which new design is created) and after the design the designer sets "is_up_to_date" value to true again? And why exactly it is setting false to "is_up_to_date"? Because we want to have consistent data during designing?
2. This happens during function SELECT DESIGNER_RUN_POPULATE_DESIGN_AND_DEPLOY?
3. Now I want to make sure with this: New projections are created from tables or old projections?
Thank you one again
Martin