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ASF GitHub Bot commented on PHOENIX-3534: ----------------------------------------- Github user twdsilva commented on a diff in the pull request: https://github.com/apache/phoenix/pull/303#discussion_r201741221 --- Diff: phoenix-core/src/main/java/org/apache/phoenix/coprocessor/MetaDataEndpointImpl.java --- @@ -2147,46 +2566,29 @@ private MetaDataMutationResult doDropTable(byte[] key, byte[] tenantId, byte[] s } if (tableType == PTableType.TABLE || tableType == PTableType.SYSTEM) { - // Handle any child views that exist - TableViewFinder tableViewFinderResult = findChildViews(region, tenantId, table, clientVersion, !isCascade); - if (tableViewFinderResult.hasViews()) { - if (isCascade) { - if (tableViewFinderResult.allViewsInMultipleRegions()) { - // We don't yet support deleting a table with views where SYSTEM.CATALOG has split and the - // view metadata spans multiple regions - return new MetaDataMutationResult(MutationCode.UNALLOWED_TABLE_MUTATION, - EnvironmentEdgeManager.currentTimeMillis(), null); - } else if (tableViewFinderResult.allViewsInSingleRegion()) { - // Recursively delete views - safe as all the views as all in the same region - for (ViewInfo viewInfo : tableViewFinderResult.getViewInfoList()) { - byte[] viewTenantId = viewInfo.getTenantId(); - byte[] viewSchemaName = viewInfo.getSchemaName(); - byte[] viewName = viewInfo.getViewName(); - byte[] viewKey = SchemaUtil.getTableKey(viewTenantId, viewSchemaName, viewName); - Delete delete = new Delete(viewKey, clientTimeStamp); - rowsToDelete.add(delete); - acquireLock(region, viewKey, locks); - MetaDataMutationResult result = doDropTable(viewKey, viewTenantId, viewSchemaName, - viewName, null, PTableType.VIEW, rowsToDelete, invalidateList, locks, - tableNamesToDelete, sharedTablesToDelete, false, clientVersion); - if (result.getMutationCode() != MutationCode.TABLE_ALREADY_EXISTS) { return result; } - } - } - } else { + // check to see if the table has any child views + try (Table hTable = + env.getTable(SchemaUtil.getPhysicalTableName( + PhoenixDatabaseMetaData.SYSTEM_CHILD_LINK_NAME_BYTES, + env.getConfiguration()))) { + boolean hasChildViews = + ViewFinder.hasChildViews(hTable, tenantId, schemaName, tableName, + clientTimeStamp); + if (hasChildViews && !isCascade) { --- End diff -- I think we can handle the race condition in a similar way to how we handle conflicting columns using checkAndMutate. I have updated PHOENIX-4799 to include this case. > 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 > Priority: Major > Fix For: 5.0.0, 4.15.0 > > Attachments: PHOENIX-3534.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 (v7.6.3#76005)