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Quanvert DSC
Introduction
The Quanvert DSC reads data from Quanvert databases. It has these features:
Feature
Quanvert database
Storage type
Folder (multiple files)
Read
Yes
Write/update
No
Unbounded loops (levels)
No
Native WHERE clause support
No
Compressed format
Yes
Multiple user read
Yes
Multiple user write
No
Data storage
Quanvert databases are optimized for tabulation. Data for each variable is stored in separate files, leading to optimal read performance for individual variables.
The Quanvert database overall storage file size (in MB) is as follows:
skidemo
UNICOM Intelligence database
UNICOM Intelligence file
Quantum
Quanvert
SPSS
Total size
19
2.18
0.9
3.25
1.7
Backup
18.1
0.65
*
2
*
The Quanvert database backup file is a pack file with a *.pkd extension. The packed format is useful for distributing Quanvert projects and for uploading Quanvert projects to UNICOM Intelligence Interviewer - Server Admin for use by UNICOM Intelligence Reporter - Survey Tabulation or UNICOM Intelligence Reporter. The pack file must be unpacked before the data can be read. Although the Quanvert DSC automatically unpacks a *.pkd file, it cannot create pack files from existing Quanvert databases.
Read performance
The following table provides the Quanvert DSC read performance (measured in seconds):
skidemo
UNICOM Intelligence database
UNICOM Intelligence file
Quantum
Quanvert
SPSS
1 variable
0.062
0.062
0.109
0.031
0.062
5 variables
0.11
0.063
0.204
0.078
0.078
All variables
1.078
0.562
0.843
0.672
0.61
▪When compared to the other DSCs, the Quanvert DSC has the best single variable read performance.
▪The Quanvert DSC does not support WHERE clauses. As a result, the Quanvert DSC does not perform as well as the DDF DSC when reading a subset of a large data set that can be filtered by a natively evaluated WHERE clause.
Write performance
The Quanvert DSC does not support the writing or updating of data. The Quanvert database must be created in Quantum.
Usage recommendations
The recommended Quanvert DSC usage is as follows:
▪Data export to other formats. The Quanvert DSC has acceptable read performance for exporting to other DSCs (when required).
The Quanvert DSC cannot simultaneously read data for more than 2039 Quanvert variables. If there are more than 2039 variables in the data set, only a subset of the variables is exported. Merging might be required to create a single output data set.
▪Tabulation. It is recommended that the Quanvert DSC be used for tabulating data that is already stored in the Quanvert database. There is no advantage in exporting the Quanvert data to another format, unless the data needs to be updated, or a large data set needs to be filtered using native WHERE clause evaluation.
The Quanvert DSC must not be used for any purposes other than tabulation or exporting to other formats.
Issues known to impact performance
The following issues are known to impact Quanvert DSC performance:
▪Quanvert multiprojects. For large Quanvert multiprojects, you can obtain better performance by first creating an MDM document (*.mdd) file, and then using the file to load the project. The UNICOM Intelligence Developer Documentation Library includes the mrScriptBasic script CreateMddFromQuanvert.mrs, which you can use to create an *.mdd file for your Quanvert project. Do not use MDM Explorer or mdmqvgen2.exe to create an *.mdd file for a multiproject, as the metadata includes Quanvert .Ex variables, which causes errors in UNICOM Intelligence Reporter.
See
Data Source Components (DSCs)