Alter table in Riak TS and new column - alter-table

I have Table having lots of data in Riak time series, but now I want to make this table alter to add some columns, How can I do that?
I tried:
alter table Person add column designation varchar(23);
I am getting the following error:
Extension alter not implemented.
Suggest me soon!

ALTER and DROP are not currently supported in Riak TS (Version 1.4) See the following question for more details: DELETE a table in Riak TS

Related

Spark(2.3) not able to identify new columns in Parquet table added via Hive Alter Table command

I have a Hive Parquet table which I am creating using Spark 2.3 API df.saveAstable. There is a separate Hive process that alters the same parquet table to add columns (based on requirements).
However, next time when I try to read the same parquet table into Spark dataframe, the new column which was added to the parquet table using Hive Alter Table command is not showing up in the df.printSchema output.
Based on initial analysis, it seems that there might be some conflict, and Spark is using its own schema instead of reading the Hive metastore.
Hence, I tried the below options :
Changing the spark setting:
spark.sql.hive.convertMetastoreParquet=false
and Refreshing the spark catalog:
spark.catalog.refreshTable("table_name")
However, the above two options are not solving the problem.
Any suggestions or alternatives would be super helpful.
This sounds like a bug described in SPARK-21841. JIRA description also contains the idea for a possible workaround:
...Interestingly enough it appears that if you create the table
differently like:
spark.sql("create table mydb.t1 select ip_address from mydb.test_table limit 1")
Run your alter table on mydb.t1 val t1 = spark.table("mydb.t1")
Then it works properly...
To fix this solution, you have to use the same alter command used in hive to spark-shell as well.
spark.sql("alter table TABLE_NAME add COLUMNS (col_A string)")

alter table/add columns in non native table in hive

I created a hive table with a storage handler and now I want to add a column to that table but it gives me below error:
[Code: 10134, SQL State: 42000] Error while compiling statement: FAILED:
SemanticException [Error 10134]: ALTER TABLE can only be used for [ADDPROPS,
DROPPROPS] to a non-native table
As per the hive documentation any hive table you create with storage handler is non native table.
Here's a link https://cwiki.apache.org/confluence/display/Hive/StorageHandlers
There is a JIRA case for enhancement is open with Apache for the same.
https://issues.apache.org/jira/browse/HIVE-1240
For ex, I am using Druid Storage Handler in my case.
I created a hive table using:
CREATE TABLE druid_table_1
(`__time` TIMESTAMP, `dimension1` STRING, `metric1` int)
STORED BY 'org.apache.hadoop.hive.druid.DruidStorageHandler';
and then I am trying to add a column:
ALTER TABLE druid_table_1 ADD COLUMNS (`dimension2` STRING);
With above approach I am getting an error.
Is there any other way to add a column to non native tables in hive without recreating it?
Patch is available in HDP 2.5+ from Hortonworks. Support for ADD columns has been added in ALTER statement.
Column can be added into druid table using ALTER table DDL in hive.
ALTER TABLE ADD COLUMNS (col_name data_type)
There is no need to specify partition spec as these are druid backed hive tables and partition/storage is maintained by druid.

Dropping table identity causes ORA-00600 error on Oracle 12c

My Oracle DB version is 12.1.0.2.0.
I'm having a hard time removing the column identity. Also tried to drop the column and dropping the table with purge command, but every time I'm getting the same Oracle error:
ORA-00600: internal error code, arguments: [12811], [96650], [], [], [], [], [], [], [], [], [], []
Just can't touch the identity column. I tried below commands but no luck:
ALTER TABLE DYS_CATEGORY MODIFY CATEGORY_ID DROP IDENTITY;
ALTER TABLE DYS_CATEGORY DROP COLUMN CATEGORY_ID;
DROP TABLE DYS_CATEGORY PURGE;
I can drop any other column from the table, but the problem is with identity column.
Identity columns are new to Oracle, just introduced in 12c.
This is a problem with Oracle 12.1.0.2.0. At least one other person has reported it (on Windows, which may be relevant).
The error you have is an ORA-00600, which is Oracle's default message for unhandled exceptions i.e. Oracle bugs. The correct answer is to raise a Service Request with Oracle Support; they will be able to provide you with a patch or a workaround if you have a corrupted table you need to fix. If you don't have a Support contract you may be out of luck.
For future reference dropping identity columns is a two-stage process:
alter table t42 modify id drop identity;
alter table t42 drop column id;
As it happens, this is not a problem on the very latest version of the product. In Oracle 18c we can just drop the column without modifying it first. LiveSQL demo.
As William said above it looks like there is/was a system generated the sequence for the identity column that was deleted but the record in idnseq$ remains intact.
I would not recommend this to anyone, but I created a new sequence called junk in the same schema. I then found the object_id for the table and the sequence I created and updated idnseq$ manually changing the seqobj# to the object_id of my new sequence for the object# of the table in question.
I was then able to drop the table and purge the recyclebin successfully.
Really don't recommend hacking oracle system tables, but this was a test system that didn't really matter and it worked.
after lots of search and hard work if the table stil showing error ORA-00600: internal error code, arguments:
Do the below step.
Take a backup of original tables
syntax: Create table original_table_back as select * from original_table;
Rename original table to some new table name
syntax: Rename original_table to original_table_1;
Rename backup to the original table
syntax: Rename Original_table_back to original_table.

Can I add a subcolumn to a hive struct column using alter table?

I've a very complex table structure in hive, let's say that it's like the following table:
create table dirceu ( a struct<b:string,c:string>);
Now I do need to add another subcolumn to the a column, and it should have the structure b,c and d, I'm trying to do it with the following alter table:
alter table dirceu change column a a struct<b:string,c:string, d:string>;
But this throw the following error:
Error: Error while processing statement: FAILED: Execution Error, return code 1 from org.apache.hadoop.hive.ql.exec.DDLTask. Unable to alter table. The following columns have types incompatible with the existing columns in their respective positions :
a (state=08S01,code=1)
Is there a way to do this using alter table? I know that I can do it using create table and copy the data, but I would like to know if there is another way to do it.
UPDATE
I'm using hive: 2.1.0.2.6.1.0-129
HortonWorks: HDP-2.6.1.0
This is the command you need to give,
ALTER TABLE dirceu CHANGE COLUMN a a STRUCT<b:STRING, c:STRING, d:STRING>;
You can't add a new field to Collection data type. Instead, you need to completely change the schema.
Hope you like the answer. Yippee!!
I guess it works by this command,
alter table dirceu add column a struct<d:string>;
Please let me know if it doesn't work by comment.

How to update Hive partitioned columns to a new set of columns?

I have a dynamic partitioned managed table in Hive partitioned by (country,state).
I wish to add one more column to these partitioned columns, say (country,state,city).
I am thinking I may use ALTER TABLE tab_nm DROP PARTITION old_partitions and then use another ALTER TABLE tab_nm ADD PARTITION.. to add new set of columns.
In one blog I read that a new table be created with latest partitions, load the data from the table with old partitions. But then I do not wish to recreate the table as its a huge production table.
I still have not implemented the ALTER TABLE.. since I am wondering that the DROP PARTITION may remove all the data in those partitions.
Please help.

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