services/horizon/internal/db2/history: Use FastBatchInsertBuilder to insert operations into history_operations

[tamirms]

PR Checklist

PR Structure

• This PR has reasonably narrow scope (if not, break it down into smaller PRs).
• This PR avoids mixing refactoring changes with feature changes (split into two PRs
  otherwise).
• This PR's title starts with name of package that is most changed in the PR, ex.
  services/friendbot, or all or doc if the changes are broad or impact many
  packages.

Thoroughness

• This PR adds tests for the most critical parts of the new functionality or fixes.
• I've updated any docs (developer docs, .md
  files, etc... affected by this change). Take a look in the docs folder for a given service,
  like this one.

Release planning

• I've updated the relevant CHANGELOG (here for Horizon) if
  needed with deprecations, added features, breaking changes, and DB schema changes.
• I've decided if this PR requires a new major/minor version according to
  semver, or if it's mainly a patch change. The PR is targeted at the next
  release branch if it's not a patch change.

What

In #4916 we introduced a FastBatchInsertBuilder which can be used to quickly insert a large amount of rows into Postgres via the COPY command. In this PR, we use FastBatchInsertBuilder to insert operations into the history_operations table.

Why

As a part of #4908 , we want to update all the code which inserts data into the history tables to use the FastBatchInsertBuilder.

Known limitations

I had to upgrade postgres to version 10+ because the COPY commands were failing with pq: invalid input syntax for type json errors when running with postgres 9.6.

see https://stackoverflow.com/questions/52334512/postgres-copy-with-command-strips-escapes-from-json-file-also-loads-each-line-a

We have discussed dropping support for postgres 9 and there seems to be a consensus that we should do this, see https://stellarfoundation.slack.com/archives/C02B04RMK/p1662747589237539

[tsachiherman]

No issues with the code itself - but I was wondering what was the trigger to remove the usage of the context ?

[tamirms]

I was wondering what was the trigger to remove the usage of the context ?

@tsachiherman

The Add() function does not take a context because the function is just appending the row to its in-memory data structures. However, the Exec() function does take a context because it is flushing all the in-memory rows to the database.