Incremental load without qvd's.

Fri, 13 Feb 2015 10:39:17 GMT

Hi Friends,

is it possible Without qvd's files we can do the incremental load in qlikview.

Thanks

Ramesh

Re: Incremental load without qvd's.

arulsettu — Fri, 13 Feb 2015 10:57:07 GMT

check this

Incremental Load without using Qvd

Re: Incremental load without qvd's.

jpenuliar — Fri, 13 Feb 2015 11:44:53 GMT

Hi Ramesh,

The reason we use QVDs is primarily the speed to load data (Optimized Load).

In general, Any data sources(txt, csv,database conns, even qvd's) are used for the initial Load, then saved to qvd for faster load for the increment part.

Yes it is possible to do incremental load without QVDs, some other BI/ETL tools can be used

Re: Incremental load without qvd's.

maxgro — Fri, 13 Feb 2015 12:00:48 GMT

Technically yes, you can use csv file, external tools

But in practice, when it comes to incremental load in QlikView you' re implicitly talking about QVD

Re: Incremental load without qvd's.

qepmalheiros — Tue, 20 Oct 2015 19:17:53 GMT

Using QVD Files for Incremental Load

Incremental load is a very common task in relation to data bases. It is defined as loading nothing but new or changed records from the database. All other data should already be available, in one way or another. With QVD Files it is possible to perform incremental load in most cases.

The basic process is described below:

1. Load the new data from Database table (a slow process, but loading a limited number of records).

2. Load the old data from QVD file (loading many records, but a much faster process).

3. Create a new QVD file.

4. Repeat the procedure for every table loaded.

The complexity of the actual solution depends on the nature of the source database, but the following basic cases can be identified:

1) Case 1: Append Only (typically log files

2) Case 2: Insert Only (No Update or Delete)

3) Case 3: Insert and Update (No Delete)

4) Case 4: Insert, Update and Delete

Below you will find outlined solutions for each of these cases. The reading of QVD files can be done in either optimized mode or standard mode. (The method employed is automatically selected by the QlikView script engine depending on the complexity of the operation.) Optimized mode is (very approximately) about 10x faster than standard mode or about 100x faster than loading the database in the ordinary fashion.

Case 1: Append Only

The simplest case is the one of log files; files in which records are only appended and never deleted. The following conditions apply:

The database must be a log file (or some other file in which records are appended and not inserted or deleted) which is contained in a text file (no ODBC/OLE DB).

QlikView keeps track of the number of records that have been previously read and loads only records added at the end of the file.

Script Example:

Buffer (Incremental) Load * From LogFile.txt (ansi, txt, delimiter is '\t', embedded labels);

Case 2: Insert Only (No Update or Delete)

If the data resides in a database other than a simple log file the case 1 approach will not work. However, the problem can still be solved with minimum amount of extra work. The following conditions apply:

The data source can be any database.

QlikView loads records inserted in the database after the last script execution.

A field ModificationDate (or similar) is required for QlikView to recognize which records are new.

Script Example:

QV_Table:

SQL SELECT PrimaryKey, X, Y FROM DB_TABLE

WHERE ModificationTime >= #$(LastExecTime)#

AND ModificationTime < #$(BeginningThisExecTime)#;

Concatenate LOAD PrimaryKey, X, Y FROM File.QVD;

STORE QV_Table INTO File.QVD;

(The hash signs in the SQL WHERE clause define the beginning and end of a date. Check your database manual for the correct date syntax for your database.)

Case 3: Insert and Update (No Delete)

The next case is applicable when data in previously loaded records may have changed between script executions. The following conditions apply:

The data source can be any database.

QlikView loads records inserted into the database or updated in the database after the last script execution

A field ModificationDate (or similar) is required for QlikView to recognize which records are new.

A primary key field is required for QlikView to sort out updated records from the QVD file.

This solution will force the reading of the QVD file to standard mode (rather than optimized), which is still considerably faster than loading the entire database.

Script Example:

QV_Table:

SQL SELECT PrimaryKey, X, Y FROM DB_TABLE

WHERE ModificationTime >= #$(LastExecTime)#;

Concatenate LOAD PrimaryKey, X, Y FROM File.QVD

WHERE NOT Exists(PrimaryKey);

STORE QV_Table INTO File.QVD;

Case 4: Insert, Update and Delete

The most difficult case to handle is when records are actually deleted from the source database between script executions. The following conditions apply:

The data source can be any database.

QlikView loads records inserted into the database or updated in the database after the last script execution.

QlikView removes records deleted from the database after the last script execution.

A field ModificationDate (or similar) is required for QlikView to recognize which records are new.

A primary key field is required for QlikView to sort out updated records from the QVD file.

This solution will force the reading of the QVD file to standard mode (rather than optimized), which is still considerably faster than loading the entire database.

Script Example:

Let ThisExecTime = Now( );

QV_Table:

SQL SELECT PrimaryKey, X, Y FROM DB_TABLE

WHERE ModificationTime >= #$(LastExecTime)#

AND ModificationTime < #$(ThisExecTime)#;

Concatenate LOAD PrimaryKey, X, Y FROM File.QVD

WHERE NOT EXISTS(PrimaryKey);

Inner Join SQL SELECT PrimaryKey FROM DB_TABLE;

If ScriptErrorCount = 0 then

STORE QV_Table INTO File.QVD;

Let LastExecTime = ThisExecTime;

End If

QlikView 11.20 SR6

Re: Incremental load without qvd's.

Anonymous — Tue, 20 Oct 2015 20:04:44 GMT

Maybe it help you.

Incremental Load in QlikView – Part1 | Learn QlikView

Incremental Load in QlikView – Part2 | Learn QlikView

Regards!!

Re: Incremental load without qvd's.

rwunderlich — Tue, 20 Oct 2015 20:12:23 GMT

malheiros‌ We appreciate your contributions. However, please do not repeat post the same replies over and over again, especially on older threads. You appear to be reposting the same two answers on any threads to do with Incremental Loads. This causes a lot of noise for others watching the Forums.

-Rob

topic Re: Incremental load without qvd's. in QlikView

Incremental load without qvd's.

Re: Incremental load without qvd's.

Re: Incremental load without qvd's.

Re: Incremental load without qvd's.

Re: Incremental load without qvd's.

Re: Incremental load without qvd's.

Re: Incremental load without qvd's.