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James Taylor commented on PHOENIX-3534: --------------------------------------- I think the child links are going to be a scaling problem. We have a split policy to keep all meta data in the same schema together, but imagine if there are 10M or even 100M child linking rows from a base table or global view to all of the children views. Let's look at how the child links are used and either: - put them in a separate table. - only store the child count with the parent table (so we know whether it has children). > Support multi region SYSTEM.CATALOG table > ----------------------------------------- > > Key: PHOENIX-3534 > URL: https://issues.apache.org/jira/browse/PHOENIX-3534 > Project: Phoenix > Issue Type: Bug > Reporter: James Taylor > Assignee: Thomas D'Silva > Attachments: PHOENIX-3534-wip.patch > > > Currently Phoenix requires that the SYSTEM.CATALOG table is single region > based on the server-side row locks being held for operations that impact a > table and all of it's views. For example, adding/removing a column from a > base table pushes this change to all views. > As an alternative to making the SYSTEM.CATALOG transactional (PHOENIX-2431), > when a new table is created we can do a lazy cleanup of any rows that may be > left over from a failed DDL call (kudos to [~lhofhansl] for coming up with > this idea). To implement this efficiently, we'd need to also do PHOENIX-2051 > so that we can efficiently find derived views. > The implementation would rely on an optimistic concurrency model based on > checking our sequence numbers for each table/view before/after updating. Each > table/view row would be individually locked for their change (metadata for a > view or table cannot span regions due to our split policy), with the sequence > number being incremented under lock and then returned to the client. -- This message was sent by Atlassian JIRA (v6.4.14#64029)