update table

Wayne_1

I have a fact table in a data warehouse. The data in some of columns is from the source data. Some of columns must be calculated based on the columns which have source data. So we have to use UPDATE to assign the calculated values for those columns. If I need to load the data to this table every night, will the UPDATE statement cause any problem? I remember Vertica does not like UPDATE statement. Thanks.

[Deleted User]

Hi,

You mean you want to run UPDATE & data load at the same time? 
Yes, that would cause lock conflicts and probably one of these operations would fail, because I lock and X lock are not compatible with each other.

Do you have any other reason to say " Vertica does not like UPDATE statement". Vertica is not optmized for DELETE/UPDATE as it is for querying (for obvious reasons). So yes, UPDATE statement may have some performance implications.

Thanks,
Pravesh

Wayne_1

Except the performance issue, does UPDATE statement cause any other issues or any limitation? Thanks.