[
https://issues.apache.org/jira/browse/HIVE-21344?focusedWorklogId=325910&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-325910
]
ASF GitHub Bot logged work on HIVE-21344:
-----------------------------------------
Author: ASF GitHub Bot
Created on: 09/Oct/19 20:46
Start Date: 09/Oct/19 20:46
Worklog Time Spent: 10m
Work Description: vineetgarg02 commented on pull request #749: HIVE-21344
URL: https://github.com/apache/hive/pull/749#discussion_r333222293
##########
File path: ql/src/java/org/apache/hadoop/hive/ql/metadata/Hive.java
##########
@@ -1612,6 +1612,150 @@ public Table
apply(org.apache.hadoop.hive.metastore.api.Table table) {
}
}
+ /**
+ * Get the materialized views that have been enabled for rewriting from the
+ * cache (registry). It will preprocess them to discard those that are
+ * outdated and augment those that need to be augmented, e.g., if incremental
+ * rewriting is enabled.
+ *
+ * @return the list of materialized views available for rewriting from the
registry
+ * @throws HiveException
+ */
+ public List<RelOptMaterialization>
getPreprocessedMaterializedViewsFromRegistry(
+ List<String> tablesUsed, HiveTxnManager txnMgr) throws HiveException {
+ // From cache
+ List<RelOptMaterialization> materializedViews =
+ HiveMaterializedViewsRegistry.get().getRewritingMaterializedViews();
+ if (materializedViews.isEmpty()) {
+ // Bail out: empty list
+ return new ArrayList<>();
+ }
+ // Add to final result
+ return filterAugmentMaterializedViews(materializedViews, tablesUsed,
txnMgr);
+ }
+
+ private List<RelOptMaterialization>
filterAugmentMaterializedViews(List<RelOptMaterialization> materializedViews,
+ List<String> tablesUsed, HiveTxnManager txnMgr) throws HiveException {
+ final String validTxnsList = conf.get(ValidTxnList.VALID_TXNS_KEY);
+ final ValidTxnWriteIdList currentTxnWriteIds =
txnMgr.getValidWriteIds(tablesUsed, validTxnsList);
+ final boolean tryIncrementalRewriting =
+ HiveConf.getBoolVar(conf,
HiveConf.ConfVars.HIVE_MATERIALIZED_VIEW_REWRITING_INCREMENTAL);
+ final long defaultTimeWindow =
+ HiveConf.getTimeVar(conf,
HiveConf.ConfVars.HIVE_MATERIALIZED_VIEW_REWRITING_TIME_WINDOW,
+ TimeUnit.MILLISECONDS);
+ try {
+ // Final result
+ List<RelOptMaterialization> result = new ArrayList<>();
+ for (RelOptMaterialization materialization : materializedViews) {
+ final RelNode viewScan = materialization.tableRel;
+ final Table materializedViewTable;
+ if (viewScan instanceof Project) {
+ // There is a Project on top (due to nullability)
+ materializedViewTable = ((RelOptHiveTable)
viewScan.getInput(0).getTable()).getHiveTableMD();
+ } else {
+ materializedViewTable = ((RelOptHiveTable)
viewScan.getTable()).getHiveTableMD();
+ }
+ final Boolean outdated =
isOutdatedMaterializedView(materializedViewTable, currentTxnWriteIds,
+ defaultTimeWindow, tablesUsed, false);
+ if (outdated == null) {
+ continue;
+ }
+
+ final CreationMetadata creationMetadata =
materializedViewTable.getCreationMetadata();
+ if (outdated) {
+ // The MV is outdated, see whether we should consider it for
rewriting or not
+ if (!tryIncrementalRewriting) {
+ LOG.debug("Materialized view " +
materializedViewTable.getFullyQualifiedName() +
+ " ignored for rewriting as its contents are outdated");
+ continue;
+ }
+ // We will rewrite it to include the filters on transaction list
+ // so we can produce partial rewritings.
+ // This would be costly since we are doing it for every materialized
view
+ // that is outdated, but it only happens for more than one
materialized view
+ // if rewriting with outdated materialized views is enabled
(currently
+ // disabled by default).
+ materialization = augmentMaterializationWithTimeInformation(
+ materialization, validTxnsList, new ValidTxnWriteIdList(
+ creationMetadata.getValidTxnList()));
+ }
+ result.add(materialization);
+ }
+ return result;
+ } catch (Exception e) {
+ throw new HiveException(e);
+ }
+ }
+
+ /**
+ * Validate that the materialized views retrieved from registry are still
up-to-date.
+ * For those that are not, the method loads them from the metastore into the
registry.
+ *
+ * @return true if they are up-to-date, otherwise false
+ * @throws HiveException
+ */
+ public boolean validateMaterializedViewsFromRegistry(List<Table>
cachedMaterializedViewTables,
+ List<String> tablesUsed, HiveTxnManager txnMgr) throws HiveException {
+ final long defaultTimeWindow =
+ HiveConf.getTimeVar(conf,
HiveConf.ConfVars.HIVE_MATERIALIZED_VIEW_REWRITING_TIME_WINDOW,
+ TimeUnit.MILLISECONDS);
+ final String validTxnsList = conf.get(ValidTxnList.VALID_TXNS_KEY);
+ final ValidTxnWriteIdList currentTxnWriteIds =
txnMgr.getValidWriteIds(tablesUsed, validTxnsList);
+ try {
+ // Final result
+ boolean result = true;
+ for (Table cachedMaterializedViewTable : cachedMaterializedViewTables) {
+ // Retrieve the materialized view table from the metastore
+ final Table materializedViewTable = getTable(
+ cachedMaterializedViewTable.getDbName(),
cachedMaterializedViewTable.getTableName());
+ if (materializedViewTable == null ||
!materializedViewTable.isRewriteEnabled()) {
+ // This could happen if materialized view has been deleted or
rewriting has been disabled.
+ // We remove it from the registry and set result to false.
+
HiveMaterializedViewsRegistry.get().dropMaterializedView(cachedMaterializedViewTable);
+ result = false;
Review comment:
It looks like as soon as we find a materialized view for which result is
false we are done. I guess we can return early in that case instead of looping
over rest of the views?
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Issue Time Tracking
-------------------
Worklog Id: (was: 325910)
Time Spent: 20m (was: 10m)
> CBO: Reduce compilation time in presence of materialized views
> --------------------------------------------------------------
>
> Key: HIVE-21344
> URL: https://issues.apache.org/jira/browse/HIVE-21344
> Project: Hive
> Issue Type: Bug
> Components: Materialized views
> Affects Versions: 4.0.0
> Reporter: Gopal Vijayaraghavan
> Assignee: Jesus Camacho Rodriguez
> Priority: Major
> Labels: pull-request-available
> Attachments: HIVE-21344.01.patch, HIVE-21344.02.patch,
> HIVE-21344.03.patch, HIVE-21344.04.patch, HIVE-21344.patch,
> calcite-planner-after-fix.svg.zip, mv-get-from-remote.png
>
> Time Spent: 20m
> Remaining Estimate: 0h
>
> For every query, {{getAllValidMaterializedViews}} still requires a call to
> metastore to verify that the materializations exist, whether they are
> outdated or not, etc. Since this is only useful for active-active HS2
> deployments, we could take a less aggressive approach and check this
> information only after rewriting has been triggered. In addition, we could
> refresh the information in the HS2 registry periodically in a background
> thread.
> {code}
> // This is not a rebuild, we retrieve all the materializations. In turn, we
> do not need
> // to force the materialization contents to be up-to-date, as this is not a
> rebuild, and
> // we apply the user parameters
> (HIVE_MATERIALIZED_VIEW_REWRITING_TIME_WINDOW) instead.
> materializations = db.getAllValidMaterializedViews(getTablesUsed(basePlan),
> false, getTxnMgr());
> {code}
> !mv-get-from-remote.png!
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