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Posted to commits@cassandra.apache.org by "Marten Kenbeek (Jira)" <ji...@apache.org> on 2021/07/01 15:53:00 UTC
[jira] [Updated] (CASSANDRA-16784) Conditional update on super
column table returns too many rows
[ https://issues.apache.org/jira/browse/CASSANDRA-16784?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Marten Kenbeek updated CASSANDRA-16784:
---------------------------------------
Description:
We have a (dense) supercolumn table that we're trying to upgrade from 2.2 to 3.x. On this table we perform conditional updates on one of the values using a CQL query. In 2.2 this works as expected: the query returns either a single-column row with {{true}}, or a two-column row with {{false}} and the current value.
In 3.x this query is internally rewritten to work on a map, using a {{Maps.SetterByKey}} operation. The update itself is applied correctly, but when the condition fails and the update is not applied, the query returns all values in the supercolumn/map instead of just the value of the subcolumn/key from the where clause.
In particular, since it returns _just_ the values, and not the keys/mapping, there's no way to know which of the values is the value of the row we're trying to update.
{code:java}
– Super column table (created through Thrift)
CREATE TABLE store.shopping_items (
key text,
column1 text,
column2 text,
"" map<text, text>,
value text,
PRIMARY KEY (key, column1, column2)
) WITH COMPACT STORAGE;
– Create some data
cqlsh:store> INSERT INTO shopping_items (key, column1, column2, value) VALUES ('item1', 'default', 'id', '1');
cqlsh:store> INSERT INTO shopping_items (key, column1, column2, value) VALUES ('item1', 'default', 'color', 'blue');
– This query returns multiple rows
cqlsh:store> UPDATE shopping_items SET value ='2' WHERE key ='item1' AND column1 = 'default' AND column2 = 'id' IF value = null;
[applied] | value
----------+-----------
False | 'blue'
False | '1'
{code}
See the attached patch for a test that succeeds on 2.2, but fails with the described behavior on 3.0 and on the latest 3.11.
was:
We have a (dense) supercolumn table that we're trying to upgrade from 2.2 to 3.x. On this table we perform conditional updates on one of the values using a CQL query. In 2.2 this works as expected: the query returns either a single-column row with {{true}}, or a two-column row with {{false}} and the current value.
In 3.x this query is internally rewritten to work on a map, using a {{Maps.SetterByKey}} operation. The update itself is applied correctly, but when the condition fails and the update is not applied, the query returns all values in the supercolumn/map instead of just the value of the subcolumn/key from the where clause.
In particular, since it returns _just_ the values, and not the keys/mapping, there's no way to know which of the values is the value of the row we're trying to update.
-- Super column table (created through Thrift)
CREATE TABLE store.shopping_items (
key text,
column1 text,
column2 text,
"" map<text, text>,
value text,
PRIMARY KEY (key, column1, column2)
) WITH COMPACT STORAGE;
-- Create some data
cqlsh:store> INSERT INTO shopping_items (key, column1, column2, value) VALUES ('item1', 'default', 'id', '1');
cqlsh:store> INSERT INTO shopping_items (key, column1, column2, value) VALUES ('item1', 'default', 'color', 'blue');
-- This query returns multiple rows
cqlsh:store> UPDATE shopping_items SET value ='2' WHERE key ='item1' AND column1 = 'default' AND column2 = 'id' IF value = null;
[applied] | value
-----------+------------
False | 'blue'
False | '1'
See the attached patch for a test that succeeds on 2.2, but fails with the described behavior on 3.0 and on the latest 3.11.
> Conditional update on super column table returns too many rows
> --------------------------------------------------------------
>
> Key: CASSANDRA-16784
> URL: https://issues.apache.org/jira/browse/CASSANDRA-16784
> Project: Cassandra
> Issue Type: Bug
> Components: Feature/Lightweight Transactions
> Reporter: Marten Kenbeek
> Priority: Normal
> Attachments: dense_supercolumn_lwt_test.patch
>
>
> We have a (dense) supercolumn table that we're trying to upgrade from 2.2 to 3.x. On this table we perform conditional updates on one of the values using a CQL query. In 2.2 this works as expected: the query returns either a single-column row with {{true}}, or a two-column row with {{false}} and the current value.
> In 3.x this query is internally rewritten to work on a map, using a {{Maps.SetterByKey}} operation. The update itself is applied correctly, but when the condition fails and the update is not applied, the query returns all values in the supercolumn/map instead of just the value of the subcolumn/key from the where clause.
> In particular, since it returns _just_ the values, and not the keys/mapping, there's no way to know which of the values is the value of the row we're trying to update.
>
> {code:java}
> – Super column table (created through Thrift)
> CREATE TABLE store.shopping_items (
> key text,
> column1 text,
> column2 text,
> "" map<text, text>,
> value text,
> PRIMARY KEY (key, column1, column2)
> ) WITH COMPACT STORAGE;
> – Create some data
> cqlsh:store> INSERT INTO shopping_items (key, column1, column2, value) VALUES ('item1', 'default', 'id', '1');
> cqlsh:store> INSERT INTO shopping_items (key, column1, column2, value) VALUES ('item1', 'default', 'color', 'blue');
> – This query returns multiple rows
> cqlsh:store> UPDATE shopping_items SET value ='2' WHERE key ='item1' AND column1 = 'default' AND column2 = 'id' IF value = null;
> [applied] | value
> ----------+-----------
> False | 'blue'
> False | '1'
> {code}
>
> See the attached patch for a test that succeeds on 2.2, but fails with the described behavior on 3.0 and on the latest 3.11.
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