Add Yezzey submodule to gpcontrib

[leborchuk]

Yezzey is an open-source extension for Apache Cloudberry and Greenplum 6 that transparently offloads Append-Only (AO/AOCO) table data to S3-compatible object storage. Inspired by Snowflake and AnyBlob, it extends the storage manager (smgr) so reads and writes go to S3 instead of local disk, keeping the user interface unchanged. A companion YProxy service acts as an I/O scheduler, managing connection pooling and request prioritization to prevent S3 throttling. Data is PGP-encrypted during upload. Benchmarks show only 10–43% query slowdown versus local storage, far outperforming PXF, making it ideal for cost-effective cold-data tiering.

The main feature of Yezzey - you don't need to change tables or code; just launch yezzey_define_offload_policy and move the data to S3. In this way, you can unload your cluster using the available disk space.

Currently, it is widely used on Greenplum 6 instances, and the goal is to provide users with the same interface in Cloudberry, so they can seamlessly migrate to Cloudberry.

We placed Yezzey as a submodule, as we believe one day we will replace all outdated solutions like AO/AOCO/Yezzey with PAX. However, that has not happened yet and we still need Yezzey.

Fixes #ISSUE_Number

What does this PR do?

Type of Change

• Bug fix (non-breaking change)
• New feature (non-breaking change)
• Breaking change (fix or feature with breaking changes)
• Documentation update

Breaking Changes

Test Plan

• Unit tests added/updated
• Integration tests added/updated
• Passed make installcheck
• Passed make -C src/test installcheck-cbdb-parallel

Impact

Performance:

User-facing changes:

Dependencies:

Checklist

• Followed contribution guide
• Added/updated documentation
• Reviewed code for security implications
• Requested review from cloudberry committers

Additional Context

CI Skip Instructions

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[leborchuk]

It's the part of our roadmap, we discussed it #868

See the item Support Compute/Storage decouple by introducing Yezzey

[tuhaihe]

We also need to add the yezzey license info to the licenses dir and LICENSE, like other submodules. FYI.

• pom.xml.

[tuhaihe]

For managing the new submodule, we can introduce it in the same way discussed here: #1084 (review)

[leborchuk]

We also need to add the yezzey license info to the licenses dir and LICENSE, like other submodules. FYI.

• pom.xml.

fixed

[leborchuk]

For managing the new submodule, we can introduce it in the same way discussed here: #1084 (review)

Yes, I did as was described. The issue is that there is no stored tag information and the tag is an ephemeral entity shown only in the git submodule output. See

xifos@xifos-dev-jammy:~/git/cloudberry-leborchuk$ git submodule status
 0da57b85cf23e48d0e515f58c65a25425dbde012 contrib/pax_storage/src/cpp/contrib/googlebench (v1.9.2-3-g0da57b8)
 52204f78f94d7512df1f0f3bea1d47437a2c3a58 contrib/pax_storage/src/cpp/contrib/googletest (release-1.8.0-3536-g52204f78)
 3a58301067bbc03da89ae5a51b3e05b7da719d38 contrib/pax_storage/src/cpp/contrib/tabulate (v1.3-51-g3a58301)
 61c03f62b370b685b7994830b570a88d05ba15ab dependency/yyjson (0.10.0-20-g61c03f6)
 a09ea700d32bab83325aff9ff34d0582e50e3997 gpcontrib/gpcloud/test/googletest (release-1.8.0-2358-ga09ea700)
 0d88f66a5fd0dba82681eef5929529cb153cb325 gpcontrib/yezzey (1.8.8)

Here yezzey linked with 1.8.8 tag but the link info is still commit hash. If I delete tag git submodule just shows commit hash without tag info