Questions tagged [batch-mode]
SQL Server batch-mode execution processes plan operator data in 64KB chunks rather than a row at a time.
6 questions
1
vote
1
answer
102
views
Does Postgres have anything analogous to Microsoft SQL Server's Batch Mode?
In traditional usages of Microsoft SQL Server, exactly one row flows from one operator in a query plan to the next. In Batch Mode, huge performance gains are obtained by moving thousands of rows at a ...
- 855
2
votes
1
answer
132
views
Does Batch Mode only apply to Agg Functions on ColumnStore Index
Azure SQL Database - Standard Edition (S3 Service Tier)
Why does Batch Mode only come into effect when using Aggregate Functions?
DROP TABLE IF EXISTS dbo.TransCS
CREATE TABLE dbo.TransCS (
...
- 513
12
votes
1
answer
286
views
Why does batch mode window aggregate yield arithmetic overflow?
The following query performs a windowed SUM over a columnstore table with 1500 total rows, each of which has the value 0 or 1, and it overflows the INT data type. Why is this happening?
SELECT a, p, ...
- 8,417
12
votes
1
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772
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How to make use of Batch Mode with an UNPIVOT (a loop join)?
I have a query of the following form:
SELECT ...
FROM ColumnstoreTable cs
CROSS APPLY (
SELECT *
FROM (VALUES
('A', cs.DataA)
, ('B', cs.DataB)
, ('C', cs.DataC)
) ...
- 1,289
8
votes
2
answers
4k
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What do the HT* wait types mean? (HTREPARTITION, HTDELETE, ...)
A big query is running right now. The result of a batch mode hash join that spills to disk is streamed into a temp table using select into. The query is showing wait types HTDELETE and HTREPARTITION ...
- 7,360
24
votes
1
answer
5k
views
What exactly can SQL Server 2014 execute in batch mode?
When a columnstore index is being used in a query SQL Server is able to use batch mode. Documentation is thin on what can run in batch mode and what can't. Please look at the following (motivating) ...
- 7,360