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help / color / mirror / Atom feedFrom: Muhammet Kurtoğlu <[email protected]>
To: mahamood hussain <[email protected]>
Cc: Brian Crockard <[email protected]>
Cc: Pgsql-admin <[email protected]>
Subject: Re: Guidance Requested: Migrating Large-Scale DB2 Databases to PostgreSQL
Date: Fri, 17 Oct 2025 23:21:06 +0300
Message-ID: <CANM7_8XbVi4EgQDAt2pj2-Am=2iv22hC_=Unh9vFtp8tpwgmZw@mail.gmail.com> (raw)
In-Reply-To: <CAGc_7HmsiEpekifed=xWpx0Cn-c8=GhOfjxai=aEFA-GSK+WDg@mail.gmail.com>
References: <CAGc_7HnBQZva+cnnm_=_pWSmrS6v217FPW7b8DC43RKXi9jqvQ@mail.gmail.com>
<[email protected]>
<CAGc_7HmsiEpekifed=xWpx0Cn-c8=GhOfjxai=aEFA-GSK+WDg@mail.gmail.com>
Hi
Open source Symetricds support bidirectonal replication from db2 to
postgresql you can look at below.
https://symmetricds.org/connectors/
There are open source topla such as pmm , graphana etc to monitor
performance of postgresql .
İ recommend to take professional support for postgresql and open source
technologies for migration.
No need o take edb support. There are lots of company that gives postgresql
professional supports with required sla.
https://www.postgresql.org/support/professional_support/
One of them is our company BiSoft located in TURKEY
www.bisoft.com.tr
*Muhammet KURTOĞLU*
T: +90(312) 220 12 20 <%2B90%28374%29%20262%2098%2000>
F: +90(312) 286 00 10 <%2B90%28374%29%20262%2090%2091>
[email protected] <[email protected]>
17 Eki 2025 Cum, saat 22:49 tarihinde mahamood hussain <
[email protected]> şunu yazdı:
> Hi Brian, Ron, Kurtoglu,
>
> Thank you all for the thoughtful responses. It took a bit of effort to
> pull this information together, but I'm glad to see the insights coming in
> — it's given me more confidence that this migration is indeed achievable
> with the right approach.
>
> To clarify our setup:
> We're currently running DB2 LUW v11.5.9 (Advanced Enterprise Server
> Edition). One of our key concerns is licensing cost, which is driving our
> move to PostgreSQL.
> A few follow-up questions based on your responses:
>
> 1.
>
> InfoSphere Data Replication (CDC):
> We understand this is a strong option, but it likely incurs additional
> licensing costs. We’re exploring Fivetran for data replication between DB2
> and PostgreSQL, with the flexibility to fall back to DB2 if performance or
> stability issues arise in production.
> -
>
> Can CDC be used for such a failback scenario (i.e., from PostgreSQL
> → DB2) similar to how Fivetran supports bidirectional sync?
> 2.
>
> Open-source Tools:
> Do we have any robust open-source tools that support both forward and
> backward replication between DB2 and PostgreSQL? This would help us plan
> for both migration and rollback scenarios without heavy vendor lock-in.
> 3.
>
> Pitfalls to Avoid During Migration:
> Since our primary goal is cost reduction, we would ideally avoid
> needing to fall back to DB2. Based on your experience, what are some common
> pitfalls or gotchas we should look out for when moving from DB2 to
> PostgreSQL?
> 4.
>
> PostgreSQL Performance Tuning & Config:
> If there’s a list of standard PostgreSQL parameters that you'd
> recommend tweaking right after installation — especially for large datasets
> — that would be very helpful. We're anticipating around 100+ concurrent
> connections during peak hours and migrating some very large tables (up to
> 80B rows).
> 5.
>
> Community vs Enterprise Support:
> In production, having support with a guaranteed response time (e.g.,
> under an hour) is crucial.
> -
>
> Does the PostgreSQL community offer any premium or paid support
> options with SLAs, or would we need to go with providers like EDB for this
> level of assurance?
>
> ------------------------------
>
>
> On Thu, Oct 16, 2025 at 6:15 PM Brian Crockard <[email protected]>
> wrote:
>
>> You may want to look into an IBM product called InfoSphere Data
>> Replciation (CDC)
>>
>>
>> https://www.ibm.com/docs/nl/idr/11.4.0?topic=requirements-supported-source-targets
>>
>> It will replicate data from DB2 to PostgreSQL. You can set it up to
>> actively replciate the data and keep it consistent. Then perform a cutover
>> at some point to the new system running against the new replicated
>> database. You will then have all of your historical data in the new system.
>> We used this on an extremely active system and it hard very few issues.
>>
>> On Wednesday, October 15, 2025 at 05:15:00 PM EDT, mahamood hussain <
>> [email protected]> wrote:
>>
>>
>> Hi Team,
>>
>> We are in the process of migrating several DB2 databases to PostgreSQL,
>> primarily to reduce the high licensing costs associated with DB2. These
>> databases support retail applications (e.g., supermarkets and stores), and
>> during peak hours, we anticipate over 100 concurrent connections.
>> ------------------------------
>> Current Database Profile:
>>
>> -
>>
>> Approximately 3,000 tables in total
>> -
>>
>> Around 100 tables contain active data
>> -
>>
>> Most tables have low data volume
>> -
>>
>> A few large tables range from 10 GB to 2 TB
>> -
>>
>> The largest table contains approximately 80 billion rows
>>
>> ------------------------------
>> Migration Approach:
>>
>> -
>>
>> We are using Ispirer for code conversion (DB2 to PostgreSQL).
>> -
>>
>> For data migration, we are evaluating Fivetran, but noted that it
>> relies on the COPY method for data loading.
>>
>> ------------------------------
>> Questions & Areas Where We Need Guidance:
>>
>> 1.
>>
>> Is Fivetran a suitable option for migrating very large datasets
>> (e.g., tables with 80+ billion rows)?
>> 2.
>>
>> Are there any reliable open-source tools for DB2 to PostgreSQL data
>> migration that we can use internally, without needing to invest in a tool
>> like Fivetran?
>> 3.
>>
>> Are there more scalable or efficient alternatives for both the
>> initial load and ongoing/incremental sync to PostgreSQL?
>>
>> ------------------------------
>> Additional Input Requested:
>>
>> -
>>
>> What are the key best practices (Do’s and Don’ts) to keep in mind
>> during a large-scale DB2 → PostgreSQL migration?
>> -
>>
>> Are there specific PostgreSQL settings or configurations we should
>> pay attention to for optimizing performance, especially for large datasets
>> and DB2-style workloads?
>>
>> ------------------------------
>>
>> We are keen to ensure performance, data integrity, and scalability
>> throughout this migration. Any insights—particularly from those with
>> experience in similar large-scale PostgreSQL implementations—would be
>> highly appreciated.
>>
>> If this is not the right forum for these questions, please do let me know
>> if there is a better place to seek this guidance.
>>
>> Thanks in advance for your support!
>>
>
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