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https://issues.apache.org/jira/browse/PHOENIX-3534?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16533116#comment-16533116
]
ASF GitHub Bot commented on PHOENIX-3534:
-----------------------------------------
Github user JamesRTaylor commented on a diff in the pull request:
https://github.com/apache/phoenix/pull/303#discussion_r200207100
--- 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 --
Isn't there a race condition with this check?
> 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.
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