[CASSANDRA-6748] If null is explicitly set to a column, paging_state will not work

• Type: Bug
• Status: Resolved
• Priority: Normal
• Resolution: Fixed
• Fix Version/s: 2.0.6

Environment

Cassandra 2.0.5
Ubuntu 12.04

• Severity: Normal
• Assignee: Sylvain Lebresne
• Reporter: Katsutoshi Nagaoka

Authors

Sylvain Lebresne

Reviewers

Aleksey Yeschenko

• Created: 21/Feb/14 03:09
• Updated: 16/Apr/19 09:31
• Resolved: 25/Feb/14 09:46

Description

If null is explicitly set to a column, paging_state will not work. My test procedure is as follows:

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Create a table and insert 10 records using cqlsh. The query is as follows:

CREATE TABLE mytable (id int, range int, value text, PRIMARY KEY (id, range));
INSERT INTO mytable (id, range) VALUES (0, 0);
INSERT INTO mytable (id, range) VALUES (0, 1);
INSERT INTO mytable (id, range) VALUES (0, 2);
INSERT INTO mytable (id, range) VALUES (0, 3);
INSERT INTO mytable (id, range) VALUES (0, 4);
INSERT INTO mytable (id, range, value) VALUES (0, 5, null);
INSERT INTO mytable (id, range, value) VALUES (0, 6, null);
INSERT INTO mytable (id, range, value) VALUES (0, 7, null);
INSERT INTO mytable (id, range, value) VALUES (0, 8, null);
INSERT INTO mytable (id, range, value) VALUES (0, 9, null);

Select 10 records using datastax driver. The pseudocode is as follows:

Statement statement = QueryBuilder.select().from("mytable").setFetchSize(1);
ResultSet rs = session.execute(statement);
for(Row row : rs){
    System.out.println(String.format("id=%d, range=%d, value=%s",
        row.getInt("id"), row.getInt("range"), row.getString("value")));
}

The result is as follows:

id=0, range=0, value=null
id=0, range=1, value=null
id=0, range=2, value=null
id=0, range=3, value=null
id=0, range=4, value=null
id=0, range=5, value=null
id=0, range=7, value=null
id=0, range=9, value=null

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Result is 8 records although 10 records were expected. I originally raised this issue in the mailing lists: http://www.mail-archive.com/[e-mail]/msg34752.html