05-async-copy-batching

Asynchronous COPY batching

This example configures the generated CopyAccounts :copyfrom query for per-shard micro-batching. Two submissions target shard-0 and coalesce into one physical COPY; a third targets shard-1 and executes independently.

The one-hour batch timeout is intentional: the program demonstrates the full EnqueueCopyAccounts → FlushCopyAccounts → Future.Await lifecycle without depending on a timer. FlushCopyAccounts forces every partial batch accepted before its barrier to execute across both physical shards.

Apply examples/sqlc/schema.sql to both databases, then set ASYNC_COPY_SHARD0_DSN and ASYNC_COPY_SHARD1_DSN before running:

go run ./examples/05-async-copy-batching

See Use asynchronous COPY batching for shutdown ordering, cancellation, partial-commit, and telemetry semantics.