[ https://issues.apache.org/jira/browse/HIVE-5851?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13829260#comment-13829260 ]
Xuefu Zhang commented on HIVE-5851: ----------------------------------- What's the serde for the case? > Hive query taking a lot of time just to launch map-reduce jobs > -------------------------------------------------------------- > > Key: HIVE-5851 > URL: https://issues.apache.org/jira/browse/HIVE-5851 > Project: Hive > Issue Type: Bug > Reporter: Sreenath S Kamath > Priority: Critical > > We are using hive for Ad-hoc querying and have a hive table which is > partitioned on two fields (date,id).Now for each date there are around 1400 > ids so on a single day around that many partitions are added.The actual data > is residing in s3. now the issue we are facing is suppose we do a select > count(*) for a month from the table then it takes quite a long amount of > time(approx : 1hrs 52 min) just to launch the map reduce job. when i ran the > query in hive verbose mode i can see that its spending this time actually > deciding how many number of mappers to spawn(calculating splits). Is there > any means by which i can reduce this lag time for the launch of map-reduce > job. this is one of the log messages that is being logged during this lag > time 13/11/19 07:11:06 INFO mapred.FileInputFormat: Total input paths to > process : 1 13/11/19 07:11:06 WARN httpclient.RestS3Service: Response > '/Analyze%2F2013%2F10%2F03%2F465' - Unexpected response code 404, expected 200 -- This message was sent by Atlassian JIRA (v6.1#6144)