Db2 to GCS
real-time replication
TwinCommit replicates IBM Db2 to Google Cloud Storage in real time by reading the Db2 transaction log and applying every committed change exactly once and in commit order. Use it to land live Db2 data in GCS as open Delta Lake or Iceberg tables, with no triggers or capture tables on the source.
Db2
log reader
commit-ordered · exactly-once
GCS
native writer
How capture works on Db2
TwinCommit reads the Db2 recovery log through the native log read API and decodes row images itself. No SQL Replication, no Q Replication, no CD tables, no triggers and no capture agents are installed on the source.
Prerequisites
- ✓Archive logging enabled (LOGARCHMETH1)
- ✓DATA CAPTURE CHANGES on each replicated table
- ✓A primary key or unique index on each replicated table
- ✓DBADM (or SYSADM) for the capture user
How apply works on GCS
Changes land as Apache Iceberg, Delta Lake or Parquet tables with one atomic commit per micro-batch. Iceberg tables register in the BigLake metastore so BigQuery can query them in place.
Requirements
- ✓Storage Object Admin on the bucket
- ✓BigLake Admin for catalog registration (optional)
- ✓Workload identity or a service-account key
Setup
Set up Db2 → GCS in four steps
- 1
Prepare Db2
Run twincommit check. It verifies archive logging enabled (logarchmeth1) and the other prerequisites, and prints the exact fix for anything missing.
- 2
Point at GCS
Add a target block for GCS. TwinCommit can generate target DDL with twincommit ddl -apply.
- 3
Snapshot
twincommit snapshot copies each table under a brief share lock and records the exact log position.
- 4
Stream
twincommit run streams every committed change from that position, exactly once and in commit order.
source:
type: db2
database: PRODDB
user: ${SRC_USER}
password: ${SRC_PASSWORD}
target:
type: gcs
bucket: acme-lake
path: replica/{schema}/{table}
format: iceberg
catalog: { type: biglake, project: acme-analytics }
tables:
- source: SALES.ORDERS
- source: SALES.ORDER_LINES
exclude_columns: [INTERNAL_NOTES]Db2 to GCS replication FAQ
How does TwinCommit replicate Db2 to GCS?
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TwinCommit reads changes from the Db2 transaction log, buffers them per transaction, and applies each committed transaction to GCS in commit order. Changes land as Apache Iceberg, Delta Lake or Parquet tables with one atomic commit per micro-batch. Iceberg tables register in the BigLake metastore so BigQuery can query them in place.
Does Db2 to GCS replication need triggers or capture tables?
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No. TwinCommit reads the Db2 log directly and creates no objects in the source database.
Is Db2 to GCS replication exactly-once?
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Yes. TwinCommit commits its checkpoint in the same GCS transaction as the data, so a crash or restart never loses or duplicates a transaction.
What Db2 versions are supported?
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Db2 LUW 11.1, 11.5, 12.1 · Db2 for z/OS 12 and 13 · Db2 on Cloud (target).
Stream Db2 to GCS today.
Download the free Developer edition, or have one of our replication engineers walk you through a migration plan.