Filter condition not correctly applied to Clustered Columnstore index

Using the below example, the predicates are the same, however the top statement (correctly) returns 0 rows, the bottom statement returns 1 - even though the predicates do NOT match:

declare @barcode nchar(22)=N'RECB012ZUKI449M1VBJZ'  
declare @tableId int = null
declare @total decimal(10, 2) = 5.17

SELECT 1
FROM
    [dbo].[transaction] WITH (INDEX([IX_Transaction_TransactionID_PaymentStatus_DeviceID_DateTime_All]))
WHERE
    Barcode = @barcode
    AND StatusID = 1
    AND TableID = @tableID
    AND @total <= Total

SELECT 1
FROM
    [dbo].[transaction] 
WHERE
    Barcode = @barcode
    AND StatusID = 1
    AND TableID = @tableID
    AND @total <= Total

Why could this be happening?

Further info:

• The Non Clustered Index in the top statement is NOT filtered

• CheckDB returns 0 issues

• Server Version: Microsoft SQL Azure (RTM) - 12.0.2000.8 Dec 19 2018 08:43:17 Copyright (C) 2018 Microsoft Corporation

Paste the Plan link:

https://www.brentozar.com/pastetheplan/?id=S1w_rU68E

Further Info:

Have ran dbcc checktable ([transaction]) with all_errormsgs, extended_logical_checks, data_purity which indicates no issues.

I can reliably reproduce the issue against this table when restoring a backup of this database.

This is a bug with SQL Server. If a column is deleted from a table with a clustered columnstore index, and then a new column is added with the same name, it appears to be using the old, deleted column for the predicate. Here is the MVCE:

This script starts off with 10000 rows with statusId of 1 and statusId2 of 5 - then drops the statusID column and renames statusId2 to statusId. So at the end all rows should have a statusId of 5.

But the following query hits the non clustered index...

select *
from example
where statusId = 1
    and total <= @filter
    and barcode = @barcode
    and id2 = @id2

... and returns 2 rows (with the selected statusId different from implied by the WHERE clause)...

+-------+---------+------+-------+----------+
|  id   | barcode | id2  | total | statusId |
+-------+---------+------+-------+----------+
|     5 |    5    | NULL |  5.00 |        5 |
| 10005 |    5    | NULL |  5.00 |        5 |
+-------+---------+------+-------+----------+

... whereas this one accesses the columnstore and correctly returns 0

select count(*) 
from example 
where statusId = 1

MVCE

/*Create table with clustered columnstore and non clustered rowstore*/
CREATE TABLE example
(
id        INT IDENTITY(1, 1),
barcode   CHAR(22),
id2       INT,
total     DECIMAL(10,2),
statusId  TINYINT,
statusId2 TINYINT,
INDEX cci_example CLUSTERED COLUMNSTORE,
INDEX ix_example (barcode, total)
);

/* Insert 10000 rows all with (statusId,statusId2) = (1,5) */
INSERT example
       (barcode,
        id2,
        total,
        statusId,
        statusId2)
SELECT TOP (10000) barcode = row_number() OVER (ORDER BY @@spid),
                   id2 = NULL,
                   total = row_number() OVER (ORDER BY @@spid),
                   statusId = 1,
                   statusId2 = 5
FROM   sys.all_columns c1, sys.all_columns c2;

ALTER TABLE example
  DROP COLUMN statusid
/* Now have 10000 rows with statusId2 = 5 */

EXEC sys.sp_rename
  @objname = N'dbo.example.statusId2',
  @newname = 'statusId',
  @objtype = 'COLUMN';
/* Now have 10000 rows with StatusID = 5 */

INSERT example
       (barcode,
        id2,
        total,
        statusId)
SELECT TOP (10000) barcode = row_number() OVER (ORDER BY @@spid),
                   id2 = NULL,
                   total = row_number() OVER (ORDER BY @@spid),
                   statusId = 5
FROM   sys.all_columns c1, sys.all_columns c2;
/* Now have 20000 rows with StatusID = 5 */

DECLARE @filter  DECIMAL = 5,
        @barcode CHAR(22) = '5',
        @id2     INT = NULL; 

/*This returns 2 rows from the NCI*/
SELECT *
FROM   example WITH (INDEX = ix_example)
WHERE  statusId = 1
       AND total <= @filter
       AND barcode = @barcode
       AND id2 = @id2;

/*This counts 0 rows from the Columnstore*/
SELECT COUNT(*)
FROM   example
WHERE  statusId = 1;

I have also raised an issue on Azure feedback portal:

And for anyone else who encounters this, rebuilding the Clustered Columnstore Index fixes the problem:

alter index cci_example on example rebuild

Rebuilding the CCI only fixes any existing data. If new records are added, the issue arises again on these records; so currently the only known fix for the table is to recreate it entirely.

StackExchange Database Administrators Q#231460, answer score: 8