use of CACHE command

[Albert-Jan Roskam]

Hi,

 

We use a thin client so we do not have local disks anymore. All disk locations, including %temp% are network locations. Given that, is there still any use to use the CACHE command (to speed up processing)? The only exception I can think of is a GET DATA command that does an SQL query, which is then followed by CACHE + EXECUTE. Am I correct in this?

 

Regards,
Albert-Jan

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
All right, but apart from the sanitation, the medicine, education, wine, public order, irrigation, roads, a
fresh water system, and public health, what have the Romans ever done for us?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 

[Jon K Peck]

From the CSR.

Although the virtual active file can vastly reduce the amount of temporary disk space required, the
absence of a temporary copy of the “active” file means that the original data source has to be reread
for each procedure. For data tables read from a database source, this means that the SQL query that
reads the information from the database must be reexecuted for any command or procedure that
needs to read the data.

Whether your disks are real or virtual, the logic is the same.

Jon Peck (no "h") aka Kim
Senior Software Engineer, IBM
[hidden email]
new phone: [phone]




From:        Albert-Jan Roskam <[hidden email]>
To:        [hidden email]
Date:        07/05/2012 03:56 AM
Subject:        [SPSSX-L] use of CACHE command
Sent by:        "SPSSX(r) Discussion" <[hidden email]>

---

Hi,
 
We use a thin client so we do not have local disks anymore. All disk locations, including %temp% are network locations. Given that, is there still any use to use the CACHE command (to speed up processing)? The only exception I can think of is a GET DATA command that does an SQL query, which is then followed by CACHE + EXECUTE. Am I correct in this?
 
Regards,
Albert-Jan


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
All right, but apart from the sanitation, the medicine, education, wine, public order, irrigation, roads, a
fresh water system, and public health, what have the Romans ever done for us?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

[Albert-Jan Roskam]

Hi Jon,

 

Thank you, this is good to know. I always thought the spatial locality was what mattered (on a local harddisk spinning next to me on my desktop  vs.  on a server in a far-away data center). I will use CACHE more liberally now. Would be fun to quantify the speed improvements.

 

Regards,
Albert-Jan

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
All right, but apart from the sanitation, the medicine, education, wine, public order, irrigation, roads, a
fresh water system, and public health, what have the Romans ever done for us?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 

From: Jon K Peck <[hidden email]>
To: [hidden email]
Sent: Thursday, July 5, 2012 2:55 PM
Subject: Re: [SPSSX-L] use of CACHE command

From the CSR.

Although the virtual active file can vastly reduce the amount of temporary disk space required, the
absence of a temporary copy of the “active” file means that the original data source has to be reread
for each procedure. For data tables read from a database source, this means that the SQL query that
reads the information from the database must be reexecuted for any command or procedure that
needs to read the data.

Whether your disks are real or virtual, the logic is the same.

Jon Peck (no "h") aka Kim
Senior Software Engineer, IBM
[hidden email]
new phone: [phone]




From:        Albert-Jan Roskam <[hidden email]>
To:        [hidden email]
Date:        07/05/2012 03:56 AM
Subject:        [SPSSX-L] use of CACHE command
Sent by:        "SPSSX(r) Discussion" <[hidden email]>

Hi,
 
We use a thin client so we do not have local disks anymore. All disk locations, including %temp% are network locations. Given that, is there still any use to use the CACHE command (to speed up processing)? The only exception I can think of is a GET DATA command that does an SQL query, which is then followed by CACHE + EXECUTE. Am I correct in this?
 
Regards,
Albert-Jan


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
All right, but apart from the sanitation, the medicine, education, wine, public order, irrigation, roads, a
fresh water system, and public health, what have the Romans ever done for us?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~