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https://issues.apache.org/jira/browse/HBASE-16935?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15683218#comment-15683218
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Mikhail Zvagelsky edited comment on HBASE-16935 at 11/21/16 11:47 AM:
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Dear Matteo, thank you very much for the explanation!
Indeed if we flush memstore before column family deletion:
{code:|borderStyle=solid}
admin.flush(tableName);
admin.deleteColumn(tableName, Bytes.toBytes("cf2"));
{code}
the family's folder disappears from file system.
Probably the deleteColumn() method should remove column family data from
memstore by default, otherwise, if used carelessly, it can produce unwanted
files.
Thank you again!
was (Author: mikhail_zvagelsky):
Dear Matteo, thank you very much for the explanation!
Indeed if we flush memstore before column family deletion:
{code:|borderStyle=solid}
admin.flush(tableName);
admin.deleteColumn(tableName, Bytes.toBytes("cf2"));
{code}
the family's folder disappears from file system.
May be the deleteColumn() method can take another boolean parameter,
e.g. "deleteFromMemory" which will indicate if memstore should be flushed
before removal of family's folder?
Thank you again!
> deleteColumn/modifyTable don't delete all family's StoreFile from file system
> -----------------------------------------------------------------------------
>
> Key: HBASE-16935
> URL: https://issues.apache.org/jira/browse/HBASE-16935
> Project: HBase
> Issue Type: New Feature
> Components: Admin
> Affects Versions: 1.2.3
> Reporter: Mikhail Zvagelsky
> Priority: Minor
> Attachments: Selection_008.png
>
>
> The method deleteColumn(TableName tableName, byte[] columnName) of the class
> org.apache.hadoop.hbase.client.Admin shoud delete specified column family
> from specified table. (Despite of its name the method removes the family, not
> a column - view the [issue|
> https://issues.apache.org/jira/browse/HBASE-1989].)
> This method changes the table's schema, but it doesn't delete column family's
> Store File from a file system. To be precise - I run this code:
> {code:|borderStyle=solid}
> import java.io.IOException;
> import org.apache.hadoop.conf.Configuration;
> import org.apache.hadoop.hbase.HBaseConfiguration;
> import org.apache.hadoop.hbase.HColumnDescriptor;
> import org.apache.hadoop.hbase.HTableDescriptor;
> import org.apache.hadoop.hbase.TableName;
> import org.apache.hadoop.hbase.client.*;
> import org.apache.hadoop.hbase.util.Bytes;
> public class ToHBaseIssueTracker {
> public static void main(String[] args) throws IOException {
> TableName tableName = TableName.valueOf("test_table");
> HTableDescriptor desc = new HTableDescriptor(tableName);
> desc.addFamily(new HColumnDescriptor("cf1"));
> desc.addFamily(new HColumnDescriptor("cf2"));
> Configuration conf = HBaseConfiguration.create();
> Connection connection = ConnectionFactory.createConnection(conf);
> Admin admin = connection.getAdmin();
> admin.createTable(desc);
> HTable table = new HTable(conf, "test_table");
> for (int i = 0; i < 4; i++) {
> Put put = new Put(Bytes.toBytes(i)); // Use i as row key.
> put.addColumn(Bytes.toBytes("cf1"), Bytes.toBytes("a"),
> Bytes.toBytes("value"));
> put.addColumn(Bytes.toBytes("cf2"), Bytes.toBytes("a"),
> Bytes.toBytes("value"));
> table.put(put);
> }
> admin.deleteColumn(tableName, Bytes.toBytes("cf2"));
> admin.majorCompact(tableName);
> admin.close();
> }
> }
> {code}
> Then I see that the store file for the "cf2" family persists in file system.
> I observe this effect in standalone hbase installation and in
> pseudo-distributed mode.
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