Hi Dev, Please find updated design documents for "*Support Database Location Configuration while Creating Database*"
Changes:
Carbon will follow the same approach as hive is following.
The table path should be formed from database location or fixed Carbon
store location and table name as given below.
*There will be three possible scenarios:*
I. Table path for the databases defined with location attribute.
tablePath = databaseLocation +”/” + tableName
II. Table path for the databases defined without location attribute.
tablePath = carbon.storeLocation + “/” + database_Name+”.db” +”/”
+ tableName
III. New table path for the default database.
tablePath = carbon.storeLocation +”/” + tableName
Regards,
Shahid
On Sat, Oct 7, 2017 at 5:26 PM, Sea <261810...@qq.com> wrote:
> Hi, Shahid:
> I think you misundertood my meaning, the databaseLocation you
> mentioned is like carbon.storeLocation, not databaseLocation in Hive.
> Your databaseLocation is like `hive.metastore.warehouse.dir`,
> The default behavior in spark(hive):
> If we do not specify database location.
> databaseLocation = hive.metastore.warehouse.dir/spark.sql.warehouse.dir
> + "/" + databaseName.db + "/" + tableName
> So databaseLocation is unique.
> If we do not specify table location:
> databaseLocation + '/' + tableName
>
> ------------------ Original ------------------
> *From: * "mohdshahidkhan1987";<mohdshahidkhan1...@gmail.com>;
> *Date: * Fri, Oct 6, 2017 08:40 PM
> *To: * "dev"<dev@carbondata.apache.org>;
> *Subject: * Re: [DISCUSSION] Support Database Location Configuration
> whileCreating Database
>
> 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
>
>
>
> --
> Sent from: http://apache-carbondata-dev-mailing-list-archive.1130556.
> n5.nabble.com/
>
Support Database Location_V2.docx
Description: MS-Word 2007 document
