如何使用HBase API删除Google Cloud Bigtable中单行的列 [英] How to delete a column of a single row in Google Cloud Bigtable with HBase API

问题描述

我正在使用HBase API来访问Google Cloud Bigtable，但是每当我尝试删除列时:

I'm using the HBase API to access Google Cloud Bigtable, but whenever I try to delete a column:

Delete delete = new Delete(r.getRow());
delete.addColumn(CF, Bytes.toBytes(d.seqid()));
delete.addColumn(CF, COL_LEASE);
tasksTable.delete(delete);

我得到一个UnsupportedOperationException:

java.lang.UnsupportedOperationException: Cannot delete single latest cell.
at com.google.cloud.bigtable.hbase.adapters.DeleteAdapter.throwIfUnsupportedPointDelete(DeleteAdapter.java:85)
at com.google.cloud.bigtable.hbase.adapters.DeleteAdapter.adapt(DeleteAdapter.java:141)
at com.google.cloud.bigtable.hbase.adapters.HBaseRequestAdapter.adapt(HBaseRequestAdapter.java:71)
at com.google.cloud.bigtable.hbase.BigtableTable.delete(BigtableTable.java:307)
at queue.BigTableRowBackedQueue.poll(BigTableRowBackedQueue.java:54)

我在我可以从HBase Java客户端删除整个行，也可以使用HBase Shell删除单个列.

I can delete the entire row fine from the HBase Java client, and I can delete individual columns fine by using the HBase shell.

如何在不删除Java客户端中的行的情况下删除列?

How can I delete columns without removing the row in the Java client?

推荐答案

很抱歉给您带来麻烦. Bigtable和HBase在几个方面有所不同，这就是其中之一.

Sorry for your troubles. Bigtable and HBase differ in a couple of ways, and this is one of them.

Delete delete = new Delete(rowKey);
delete.addColumns(COLUMN_FAMILY, qual); // the 's' matters
table.delete(delete);

HBase的Delete.addColumn仅从列中删除最新的单元格. Delete.addColumn_s_表示删除所有单元格(即所有各种时间戳记).或者，您可以通过Delete.addColumn(byte[], byte[], long)删除特定的单元格，其中long是时间戳.

HBase's Delete.addColumn deletes only the latest cell from the column. The Delete.addColumn_s_ means delete all cells (i.e. all the various timestamps). Alternatively, you can delete a specific cell via Delete.addColumn(byte[], byte[], long) where the long is a timestamp.

hbase shell删除使用 deleteColumns，它映射到封面下的addColumns.它还使用s变体，这就是它起作用的原因.

The hbase shell delete uses deleteColumns which maps to addColumns under the cover. It also uses the s variation, which is why it works.

供参考

For reference here is our complete TestDelete suite which identify the use case you present as @Category(KnownGap.class) which we use to identify differences missing HBase features in the Bigtable client.

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