Working with the metadata database

This section describes how Flexter metadata database can be accessed to gain further insight into you data.

Set up

You can generate useful applications from the metadata repository. Flexter ships with a report on data lineage (source to target map) and provides an ER diagram of the target schema.

Flexter’s metadata repository is a PostgreSQL database.

You can log in to the metadata database using a SQL workbench tool that supports JDBC, e.g. DBeaver.

Database name: x2er
Username: flex2er
Password: The password you set when installing the metadata repository

Preparation

To generate a data lineage report (tsv format; can be opened in Excel) or an ER diagram (graphml format readable by eg. yEd), you need to have two pieces of information:

- Id_sch ( origin ID that you pass as -x parameter to xml2er )
- Id_lschma ( ID that you pass as -l parameter to xml2er )

You can obtain these IDs from Flexter output under #schema section:

origin = id_sch
logical = id_lschma

Alternatively, you can query these values from Flexmeta postgresql database with the following query:

SELECT s.sch_name, s.id_sch, m.id_lschma
FROM schma s
JOIN mapping m ON m.id_sch=s.id_sch;

Once you have both IDs, you can generate mappings and diagrams by running scripts from flexchma package. The packages can be found under /usr/share/flexter/flexchma/aux/

Data lineage report

During the install Flexter installs various helper scripts to generate data lineage and visual ER diagrams.

Run the metadb.aux.genmapdoc.sh script to generate a data lineage file as TSV, which can be opened in Excel.

$ /usr/share/flexter/flexchma/aux/metadb.aux.genmapdoc.sh 50 28 localhost /tmp/50.28.mapping.tsv

1st parameter - id_sch
2nd parameter - id_lschma
3rd parameter - hostname of flexmeta postgresql database
4th parameter - output path

Flexter ER diagram

$ /usr/share/flexter/flexchma/aux/metadb.aux.tgt.gengraphml.sh 50 28 localhost /tmp/50.28.diagram.graphml

1st parameter - id_sch
2nd parameter - id_lschma
3rd parameter - hostname of flexmeta PostgreSQL database
4th parameter - output path

You can open the generated file in any tool that supports graphml files, for example yEd.

Data model for metadata database

You can reverse engineer the metadata data model using a modeling tool that supports PostgreSQL, e.g. DBSchema.

Alternatively you can download a PDF version of the data model.

Please contact Sonra support for some useful scripts for querying the Metadata DB.

You can also use the diagram below as reference