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https://issues.apache.org/jira/browse/DRILL-4577?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15231742#comment-15231742
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ASF GitHub Bot commented on DRILL-4577:
---------------------------------------
Github user hsuanyi commented on a diff in the pull request:
https://github.com/apache/drill/pull/461#discussion_r58986459
--- Diff:
contrib/storage-hive/core/src/main/java/org/apache/drill/exec/store/hive/schema/HiveDatabaseSchema.java
---
@@ -72,4 +80,76 @@ public String getTypeName() {
return HiveStoragePluginConfig.NAME;
}
+ @Override
+ public List<Pair<String, ? extends Table>> getTablesByNames(final
List<String> tableNames) {
+ final String schemaName = getName();
+ final List<Pair<String, ? extends Table>> tableNameToTable =
Lists.newArrayList();
+ List<org.apache.hadoop.hive.metastore.api.Table> tables;
+ // Retries once if the first call to fetch the metadata fails
+ synchronized(mClient) {
+ final List<String> tableNamesWithAuth = Lists.newArrayList();
+ for(String tableName : tableNames) {
+ try {
+ if(mClient.tableExists(schemaName, tableName)) {
--- End diff --
We have some discussions in the background. So let me summarize them below:
Here are some findings:
There are two ways for authorization, "SQL Standard Based Authorization"
and "Storage Based Authorization" [1]. When "Storage Based Authorization" is
being used, and we use "getTableObjectsByName", the returned results will
display some tables, which are not authorized to this user.
The reason is when "getTableObjectsByName" is being used, hive meta storage
will return the tables which are not authorized to the users. Since the issue
is in Hive, currently I do not think there is a simple fix.
On the other hand, "SQL Standard Based Authorization" would not have this
issue.
[1]
https://drill.apache.org/docs/configuring-user-impersonation-with-hive-authorization/
> Improve performance for query on INFORMATION_SCHEMA when HIVE is plugged in
> ---------------------------------------------------------------------------
>
> Key: DRILL-4577
> URL: https://issues.apache.org/jira/browse/DRILL-4577
> Project: Apache Drill
> Issue Type: Improvement
> Components: Storage - Hive
> Reporter: Sean Hsuan-Yi Chu
> Assignee: Sean Hsuan-Yi Chu
> Fix For: 1.7.0
>
>
> A query such as
> {code}
> select * from INFORMATION_SCHEMA.`TABLES`
> {code}
> is converted as calls to fetch all tables from storage plugins.
> When users have Hive, the calls to hive metadata storage would be:
> 1) get_table
> 2) get_partitions
> However, the information regarding partitions is not used in this type of
> queries. Beside, a more efficient way is to fetch tables is to use
> get_multi_table call.
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