feature(ehi): Adding high volume EHI example

[fivetran-sahilkhirwal]

Jira ticket

Closes https://fivetran.atlassian.net/browse/RD-1172756

Description of Change

• Adding high volume EHI example

Testing

Checklist

Some tips and links to help validate your PR:

• Tested the connector with fivetran debug command.
• Added/Updated example-specific README.md file, see the README template for the required structure and guidelines.
• Followed Python Coding Standards, refer here

[github-actions]

🧹 Python Code Quality Check

✅ No issues found in Python Files.

🔍 See how this check works

This comment is auto-updated with every commit.

[Copilot]

Pull request overview

This pull request adds two new EHI (Microsoft SQL Server / Caboodle-style) Connector SDK examples—one “simple” connector and one “high volume” connector—and updates the repository’s top-level connector index to reference both variants.

Changes:

• Update the top-level README.md connector list to point to two EHI example variants.
• Add a simple_ehi connector example using python-tds with basic schema discovery, batch fetching, and incremental sync based on a modified-date column.
• Add a high_volume_ehi connector example using pyodbc with parallel schema discovery, keyset/offset pagination readers, and threaded table syncing.

Reviewed changes

Copilot reviewed 9 out of 13 changed files in this pull request and generated 12 comments.

Show a summary per file

File	Description
README.md	Splits the EHI entry into simple_ehi and high_volume_ehi references.
connectors/ehi/simple_ehi/requirements.txt	Adds the python-tds dependency for the simple connector.
connectors/ehi/simple_ehi/README.md	Adds documentation for the simple EHI connector example.
connectors/ehi/simple_ehi/connector.py	Implements the simple EHI connector (schema discovery + sync loop + state/checkpointing).
connectors/ehi/simple_ehi/configuration.json	Adds placeholder configuration for the simple connector.
connectors/ehi/high_volume_ehi/requirements.txt	Adds dependencies for the high-volume connector (currently includes requests).
connectors/ehi/high_volume_ehi/README.md	Adds documentation for the high-volume EHI connector example.
connectors/ehi/high_volume_ehi/readers.py	Adds keyset/offset/incremental reader implementations.
connectors/ehi/high_volume_ehi/models.py	Adds schema detection + replication key detection logic.
connectors/ehi/high_volume_ehi/constants.py	Adds performance/retry/tuning constants.
connectors/ehi/high_volume_ehi/connector.py	Implements the high-volume connector orchestration and threaded table syncing.
connectors/ehi/high_volume_ehi/configuration.json	Adds placeholder configuration for the high-volume connector.
connectors/ehi/high_volume_ehi/client.py	Adds a pyodbc connection wrapper + pooled acquire/retry behavior.

[fivetran-satvikpatil]

@codex review

[fivetran-JenasVimal]

Please address the comments

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: d6c6bc312b

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[fivetran-satvikpatil]

Please address one comment, else LGTM. Also please add testing details again after the changes.