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Re: [DISCUSSION] Support Database Location Configuration while Creating Database

Posted by mohdshahidkhan on Oct 06, 2017; 12:40pm
URL: http://apache-carbondata-dev-mailing-list-archive.168.s1.nabble.com/DISCUSSION-Support-Database-Location-Configuration-while-Creating-Database-tp23492p23546.html

Hi Sea,

1. create database with location is supported by spark(hive) only, carbon
will not have any own implementation for create database. It is mention here
just for reference regarding the location attribute.
2. Why carbon want to keep tablePath = 'databaseLocation  “/” +
database_Name + "/" + tableName`
   
 There is problem if we keep the tablePath same as hive. For
CarbonFileMetaStore, carbon creates
 the schema file at  <TablePath>/Metadata/schema

If carbon skips adding databaseName, then two table having same name from
two different databases pointing to the same database location will cause
problem during table creation, load and query.

Even in case hive if two tables in different databases with same are
created, then we are showing then when either of the table is queried, the
content from both the tables are shown.

3. What does `Carbon.update.sync.folder` means?
 This is to configure the directory for modifiedTime.mdt.
 Earlier the directory path for modifiedTime.mdt was fixed to
carbon.storeLocation, but what if user           decides to remove the name
service of the  carbon.storeLocation.
 This is required for the federation cluster, where multiple name services
will be available. So if the     nameservice to which the the directory for
modifiedTime.mdt is removed then  the directory could be
 changed.

Regards,
Shahid



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