A few weeks back got a chance to attend Oracle’s Real World performance tuning class. This class was using Exadata hardware and Oracle 12c edition. A very interesting set of findings that I would like to present here:-
A typical Informatica MDM implementation uses Informatica ETL tool for processing data to the Landing tables, and may have one or more stages, depending on the architecture, for processing data from various in house or third party data providers; processing from Landing to Staging to Various target tables(cross reference, and associated tables), tokenization of these records and then match merge in the Informatica MDM space; and then generating feeds to various downstream data marts, data warehouses, OLTP systems, and third parties. In my experience a majority of this work happens with the Powercenter and MDM toolsets from Informatica. Though in this realm work can be and is done using Web Services, but for the purpose of this article, I shall ignore that use case.
Once a system is in place, it needs to be monitored for ensuring ongoing data quality and performance. This tends to be a tedious task because not only are there multiple stages to the whole processing before, during and after MDM processing of the data, but also the performance metrics are stored in two different repositories. This article show what data is available in those repositories and how one could set some naming patterns as part of the standards while architecting such a system that would make it not only possible, but approach the whole effort in an efficient manner.
So let us explore what both the repositories provide, starting with Informatica Powercenter repository:-
Powercenter repository provides and can be leveraged to get a multitude of reports as shown here. For the purpose of this blog I shall be using the following tables:-
The first table could be queried to get the various workflows/worklets/sessions that are available in the repository. I use the following query to get the information about the workflow and the other artifacts contained therein in a hierarchical fashion.
AS (SELECT *
FROM (SELECT connect_by_root workflow_id the_workflow_id
Sys_connect_by_path (instance_name, '/')
FROM (SELECT *
FROM opb_task_inst ta
WHERE task_type <> 62
AND version_number = (SELECT
FROM opb_task_inst ti2
ti2.instance_id = ta.instance_id))
WHERE connect_by_isleaf = 1
START WITH ti.workflow_id IN (SELECT task_id
WHERE task_type = 71)
CONNECT BY PRIOR ti.task_id =ti.workflow_id) q
WHERE q.task_type <> 70),
AS (SELECT subject_id,
FROM (SELECT subject_id,
PARTITION BY subject_id, task_id
ORDER BY version_number DESC) trn
WHERE task_type = 71) q
WHERE q.trn = 1)
SELECT f.subj_name folder_name,
FROM session_cfg_info s
join workflow_cfg_info w
ON ( s.the_workflow_id = w.the_workflow_id )
join opb_subject f
ON ( f.subj_id = w.subject_id )
We shall come to the use of this result set later.
Next we gather the run time information about various jobs that ran using the following query as a starting point.
SELECT workflow_id, rn, workflow_run_id, worklet_run_id, child_run_id,
task_id, instance_id, instance_name,
workflow_id || SYS_CONNECT_BY_PATH (task_id, ',') full_task_id,
SYS_CONNECT_BY_PATH (instance_name, '/') fully_qualified_name,
FROM (SELECT workflow_id, workflow_run_id, worklet_run_id, child_run_id,
REPLACE (run_err_msg, CHR (10), ' ') run_err_msg,
WHEN child_run_id = 0
* (ROW_NUMBER () OVER (ORDER BY end_time,
FROM opb_task_inst_run t
WHERE task_type <> 62) q
WHERE CONNECT_BY_ISLEAF = 1
CONNECT BY NOCYCLE PRIOR rn = worklet_run_id
AND PRIOR workflow_run_id = workflow_run_id
START WITH worklet_run_id = 0
Joining this information with the data from the opb_sess_task_log table, the opb_wflow_run tab and opb_subject table, one can derive the information to be able to join with the data from the workflow configuration data derived in the first query above. One has to be careful as the opb_sess_task_log will have higher cardinality than the workflow run query provide immediately above. If I am trying to monitor things at each and source qualifier or target level it, we could join it directly. However, if one is just trying to get a ball park idea of the volumes processed it might as well be aggregated, and that may provide good enough information for trending the performance numbers. For this exercise let us go with the latter:-
SUM (src_failed_rows) src_failed_rows,
SUM (targ_success_rows) targ_success_rows,
SUM (targ_failed_rows) targ_failed_rows,
SUM (total_trans_errs) total_trans_errs
FROM etl_prd_rep.opb_sess_task_log tl
GROUP BY workflow_run_id, instance_id
So having discussed the Powercenter repository queries, let us review the provided results. If your implementation is like any that I have seen at multiple organizations, you would find that the sessions running MDM job stored procedures are reporting either 1 or 0 rows processed, depending on how the stored procedure is being called. This just ends up giving the run timings. If you are lucky the implementation may even record error when the MDM job fails. But, the number of rows are not reported back. So to address this deficiency, let us move on the MDM repository schema. Here the queries are straight forward to obtain information about various jobs:
SELECT jc.rowid_job job_run_id,jc.system_name data_system,
jc.table_display_name subject_table_name,jc.object_desc job_desc,
WHERE job_status_code = jc.run_status)run_status,status_message,
WHERE object_function_type_code =
jc.start_run_date start_date, jc.end_run_date end_date,
jn.total_records, jn.inserted_records, jn.updated_records,
jn.no_action_records, jn.matched_records, jn.updatedxref_records,
FROM c_repos_table t JOIN c_repos_job_control jc
ON (t.rowid_table = jc.rowid_table)
LEFT OUTER JOIN
WHEN metric_type_code = 1
WHEN metric_type_code = 2
WHEN metric_type_code = 3
WHEN metric_type_code = 4
WHEN metric_type_code = 5
FROM c_repos_job_metric jm
GROUP BY rowid_job) jn ON (jc.rowid_job = jn.rowid_job)
Again I chose to report the statistics in a row, but decided not to aggregate as that wonâ€™t always make sense to add these numbers. Also, I am showing only a few stats in the query, other metrics are available as well.
Now, we come to the real challenge. The challenge lies in being able to combine the rows from the Informatica repository with those from the MDM repository. One could follow the approach whereby one could create characterize the data pulled from both the repositories with common attributes. Here we go back to the purpose of the very first query from this article. We could e.g. gather that data in a table where we could add extra attributes that would help us characterize those sessions/jobs. We would follow a similar approach in case of the MDM data. We would need to make sure that whenever we add new jobs on ETL/MDM side that we add those rows to these characterization tables. Using these characterization tables and knowing the fact that on a reasonably time synchronized platform the ETL jobs timing would be same or a little outside the MDM job timing, we could combine the rows exactly and get all the relevant stats from the MDM system.
On a multi-domain MDM system the following attributes would be sufficient:-
a. Domain (Customer/Product)
b. Source System (Admin or others..)
c. Operation (Landing, Staging, Loading, Auto Match & Merge, etc.)
d. Table Name or MDM Target Object.
For joining the ETL run information with the configuration donâ€™t forget to use the fully qualified task id, as that takes care of the various shared objects use in multiple parent objects.
While building one such system, I was able to use the various patterns in names to find these attributes. Since, I approached this problem after the fact of building the system in first place, this task was not trivial, but was made easy by a consistent use of naming conventions. If I was leading the build process I think this task can be further simplified, and can be more easily incorporated into the initial build itself.
When doing a code review one looks to see if the best practices are followed. Some are about the readability and therefore maintainability of the code, but, then there are some which could point to application logic traps. While reviewing a SQL I found something in production code, leading me to believe it could/should have been caught more easily with a code review itself, though there is no excuse that it was not found with the data validation/qa step.
The pattern is as following:- Select grouping_attribute , max(descriptor_type_attribute), max(attribute_expiry_date)
From table Group by grouping_attribute The data has to do with licensing of certain professionals, and the descriptor_type_attribute is the identifier given by the licensing board and will have any expiry date associated with it. This query would have been fine if both the attributes followed the same sorting strategy, but it was not the case. So one could end up picking up a license number(descriptor_type_attribute) with wrong expiry date. Not the intended outcome. Part of the fault in my humble opinion lies with giving a _no postfix to the descriptor_type_attribute in the data model. A better query could be written using the analytical functions in Oracle, e.g.
Select grouping_attribute, descriptor_type_attribute, attribute_expiry_date from (
Select grouping_attribute, descriptor_type_attribute, attribute_expiry_date,
Row_number() over(partition by grouping_attribute order by attribute_expiry_date desc) rn
About Sarbjit Parmar
A practitioner with technical and business knowledge in areas of Data Management( Online transaction processing, data modeling(relational, hierarchical, dimensional, etc.), S/M/L/XL/XXL & XML data, application design, batch processing, analytics(reporting + some statistical analysis), MBA+DBA), Project Management / Product/Software Development Life Cycle Management.