SQL Server to S3
real-time replication
TwinCommit replicates Microsoft SQL Server to Amazon S3 in real time by reading the SQL Server transaction log and applying every committed change exactly once and in commit order. Use it to land live SQL Server data in S3 as open Delta Lake or Iceberg tables, with no triggers or capture tables on the source.
SQL Server
log reader
commit-ordered · exactly-once
S3
native writer
How capture works on SQL Server
TwinCommit reads the active and backed-up transaction log directly, so you do not need SQL Server Agent CDC jobs or change tables.
Prerequisites
- ✓FULL recovery model
- ✓Primary key on each replicated table
- ✓VIEW SERVER STATE and db_owner on the source database
How apply works on S3
Changes land as Apache Iceberg, Delta Lake or Parquet tables, one atomic commit per micro-batch with the checkpoint in the snapshot metadata. Iceberg tables register in AWS Glue or Amazon S3 Tables automatically.
Requirements
- ✓IAM role with s3:GetObject, PutObject, DeleteObject and ListBucket on the prefix
- ✓Glue catalog permissions for table registration
- ✓Same-region placement recommended
Setup
Set up SQL Server → S3 in four steps
- 1
Prepare SQL Server
Run twincommit check. It verifies full recovery model and the other prerequisites, and prints the exact fix for anything missing.
- 2
Point at S3
Add a target block for S3. 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: sqlserver
dsn: ${SOURCE_DSN}
target:
type: s3
bucket: acme-lake
path: replica/{schema}/{table}
format: iceberg
catalog: { type: glue, database: replica }
tables:
- source: SALES.ORDERS
- source: SALES.ORDER_LINES
exclude_columns: [INTERNAL_NOTES]SQL Server to S3 replication FAQ
How does TwinCommit replicate SQL Server to S3?
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TwinCommit reads changes from the SQL Server transaction log, buffers them per transaction, and applies each committed transaction to S3 in commit order. Changes land as Apache Iceberg, Delta Lake or Parquet tables, one atomic commit per micro-batch with the checkpoint in the snapshot metadata. Iceberg tables register in AWS Glue or Amazon S3 Tables automatically.
Does SQL Server to S3 replication need triggers or capture tables?
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No. TwinCommit reads the SQL Server log directly and creates no objects in the source database.
Is SQL Server to S3 replication exactly-once?
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Yes. TwinCommit commits its checkpoint in the same S3 transaction as the data, so a crash or restart never loses or duplicates a transaction.
What SQL Server versions are supported?
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SQL Server 2016–2025 · Azure SQL Managed Instance · Azure SQL Database (target).
Stream SQL Server to S3 today.
Download the free Developer edition, or have one of our replication engineers walk you through a migration plan.