Executing Multiple Queries One By One

Database
Enthusiast

Executing Multiple Queries One By One

Hi Experts,

 

I have 10 queries which are to be run on Teradata sql assistant. I have following questions around this scenario

 

1. From performance perspective does it matter if I run 1 query at a time vs all 10 queries in one go. 

2. If I run 10 queries together , will it consume more spool usage vs 1 query at a time?

 

Thanks,

Niel

5 REPLIES
Teradata Employee

Re: Executing Multiple Queries One By One

it depends on the queries. either way, the performance should not be worse if you run them all at once. but if there is overlap in the objects used or the spool files used, then the queries will actually run faster if they are executed at the same time.

Senior Apprentice

Re: Executing Multiple Queries One By One

Another difference:

Submitted as a Multi Statement Request it might be faster overall, but you get all answer sets after all queries are finished and if one is failing you get none.

Whereas submitted as individual Selects you get each result after a query finished.

Enthusiast

Re: Executing Multiple Queries One By One

Thanks. I have one follow up questtion on this .....

what if I am running multistatements but its failing because of spool space issue, do you think running them one by one will help.

In short , if I run multistatements , does it accumulate spool space as compare to running them one by one?

Teradata Employee

Re: Executing Multiple Queries One By One

Yes, running queries at the same time will likely mean that your Current Spool will be larger. So if you are running a bunch of queries simultaneously and hitting your max spool, you can try running them sequentially.

Enthusiast

Sample Script

Hi Dieter.

 

Can you please help me to get sample script to load XML file into table. 

 

I have source as XML file. I need to load the data into tables. 

 

I have multiple repetitive blocks in XML with huge columns with data. 

 

Thanks in advance