diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index c56ea6f..34b62bf 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -5,9 +5,12 @@ on:
     branches: [ main ]
   pull_request:
     branches: [ main ]
+  workflow_dispatch:
+  schedule:
+    - cron: "0 6 * * 0"
 
 jobs:
-  test:
+  test-core:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
@@ -15,6 +18,19 @@ jobs:
         run: |
           make
           sudo make install
-      - name: Run tests
+      - name: Run core tests
         run: |
           docker compose up --abort-on-container-exit --exit-code-from test test
+
+  test-slow-suites:
+    if: github.event_name == 'schedule' || github.event_name == 'workflow_dispatch'
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Build and install extension
+        run: |
+          make
+          sudo make install
+      - name: Run integration and performance suites
+        run: |
+          docker compose run --rm -e RUN_INTEGRATION=1 -e RUN_PERF=1 test make test-all
diff --git a/README.md b/README.md
index bcb2009..3dd143b 100644
--- a/README.md
+++ b/README.md
@@ -111,19 +111,26 @@ CREATE EXTENSION pg_git;
 
 ## Testing
 
-`make test` now runs a preflight (`test-preflight`) before executing SQL TAP tests. The preflight checks:
-- PostgreSQL connectivity using `PGHOST`, `PGPORT`, `PGUSER`, `PGDATABASE`
-- required extensions are enabled (`pgcrypto`, `pg_trgm`, `plpython3u`)
-- `pg_prove` is installed and on `PATH`
+Test suites are split by speed and external dependencies:
 
-### Known-good test matrix
+- `test-core` (default): deterministic SQL tests for local logic. **Expected runtime:** ~10-30 seconds in Docker on a modern laptop. **Prerequisites:** running PostgreSQL test database.
+- `test-integration` (opt-in): HTTPS transport checks in `test/sql/https_fetch_test.sql`. **Expected runtime:** ~30-90 seconds depending on network/container startup. **Prerequisites:** set `RUN_INTEGRATION=1`; `plpython3u` available; outbound HTTPS/network available.
+- `test-performance` (opt-in): GC performance regression checks in `test/sql/gc_performance_test.sql`. **Expected runtime:** ~1-5+ minutes depending on machine load. **Prerequisites:** set `RUN_PERF=1`; stable CPU/IO for consistent measurements.
+- `test-all`: runs `test-core` and then conditionally runs integration/performance suites when their flags are enabled.
 
-| Environment | Connection setup | Test command |
-| --- | --- | --- |
-| Local PostgreSQL | `export PGHOST=localhost PGPORT=5432 PGUSER=postgres PGDATABASE=postgres` | `make test` |
-| Docker Compose (`db` service) | `PGHOST=db PGPORT=5432 PGUSER=postgres PGDATABASE=pg_git_dev` (already set in `docker-compose.yml`) | `docker-compose run --rm test` |
+```bash
+# Fast default suite (also what `make test` runs)
+make test-core
+
+# Explicitly include HTTPS/integration tests
+RUN_INTEGRATION=1 make test-integration
 
-If preflight fails, fix the reported prerequisite and re-run `make test`.
+# Explicitly include performance tests
+RUN_PERF=1 make test-performance
+
+# Run everything (slow suites run only when flags are set)
+RUN_INTEGRATION=1 RUN_PERF=1 make test-all
+```
 
 ## Development
 Using Docker:
diff --git a/makefile b/makefile
index f3388d1..320a421 100644
--- a/makefile
+++ b/makefile
@@ -25,9 +25,28 @@ DATA = \
        $(wildcard sql/schema/*.sql) \
        $(wildcard sql/functions/*.sql)
 
-# Authoritative test order lives in test/sql/manifest.txt.
-TEST_MANIFEST := test/sql/manifest.txt
-TESTS := $(shell sed -e '/^[[:space:]]*#/d' -e '/^[[:space:]]*$$/d' $(TEST_MANIFEST))
+# Deterministic, fast SQL tests that run on every change.
+CORE_TESTS := \
+       test/sql/init.sql \
+       test/sql/add_test.sql \
+       test/sql/branch_test.sql \
+       test/sql/commit_test.sql \
+       test/sql/diff_test.sql \
+       test/sql/merge_test.sql \
+       test/sql/remote_test.sql \
+       test/sql/advanced_test.sql \
+       test/sql/gc_test.sql \
+       test/sql/optimize_indexes_test.sql
+
+# Slower/less deterministic suites are opt-in.
+INTEGRATION_TESTS := \
+       test/sql/https_fetch_test.sql
+
+PERFORMANCE_TESTS := \
+       test/sql/gc_performance_test.sql
+
+# Backward-compatible aggregate for PGXS regress helpers.
+TESTS := $(CORE_TESTS) $(INTEGRATION_TESTS) $(PERFORMANCE_TESTS)
 
 # Derive the target names from the TESTS list to keep them in sync.
 REGRESS := $(notdir $(basename $(TESTS)))
@@ -35,46 +54,26 @@ REGRESS_OPTS = --inputdir=test
 
 include $(PGXS)
 
-.PHONY: test test-preflight
-
-test-preflight:
-	@command -v pg_prove >/dev/null 2>&1 || { \
-		echo "ERROR: pg_prove is not installed or not on PATH."; \
-		echo "Install it via your package manager (often in postgresql-test/perl-Test-Harness-TAP packages)."; \
-		exit 1; \
-	}
-	@$(PSQL) -c 'SELECT 1;' >/dev/null || { \
-		echo "ERROR: unable to connect to PostgreSQL using PGHOST=$(PGHOST) PGPORT=$(PGPORT) PGUSER=$(PGUSER) PGDATABASE=$(PGDATABASE)."; \
-		echo "Check credentials, host reachability, and that the database exists."; \
-		exit 1; \
-	}
-	@$(PSQL) -tA -c "SELECT string_agg(e, ', ') FROM (VALUES ('pgcrypto'),('pg_trgm'),('plpython3u')) AS req(e) WHERE NOT EXISTS (SELECT 1 FROM pg_extension WHERE extname = req.e);" | \
-		awk 'NF { printf "ERROR: missing required extensions: %s\n", $$0; print "Install with: CREATE EXTENSION <name>;"; exit 1 }'
-	@echo "Preflight checks passed for PGHOST=$(PGHOST) PGPORT=$(PGPORT) PGUSER=$(PGUSER) PGDATABASE=$(PGDATABASE)."
-
-test: test-preflight
-	pg_prove -h $(PGHOST) -p $(PGPORT) -U $(PGUSER) -d $(PGDATABASE) $(TESTS)
-
-.PHONY: test test-one test-one-verbose test-list
-test:
-	pg_prove -d postgres $(TESTS)
-
-# Focused rerun for a single SQL test file: make test-one TEST=test/sql/merge_test.sql
-test-one:
-	@if [ -z "$(TEST)" ]; then \
-		echo "Usage: make test-one TEST=test/sql/<file>.sql"; \
-		exit 1; \
+.PHONY: test test-core test-integration test-performance test-all
+
+# Keep `make test` as fast default.
+test: test-core
+
+test-core:
+	pg_prove -d postgres $(CORE_TESTS)
+
+test-integration:
+	@if [ "$(RUN_INTEGRATION)" != "1" ]; then \
+		echo "Skipping integration tests. Set RUN_INTEGRATION=1 to run them."; \
+		exit 0; \
 	fi
-	pg_prove -d postgres $(TEST)
+	pg_prove -d postgres $(INTEGRATION_TESTS)
 
-# Verbose focused rerun for richer diagnostics
-test-one-verbose:
-	@if [ -z "$(TEST)" ]; then \
-		echo "Usage: make test-one-verbose TEST=test/sql/<file>.sql"; \
-		exit 1; \
+test-performance:
+	@if [ "$(RUN_PERF)" != "1" ]; then \
+		echo "Skipping performance tests. Set RUN_PERF=1 to run them."; \
+		exit 0; \
 	fi
-	pg_prove -v -d postgres $(TEST)
+	pg_prove -d postgres $(PERFORMANCE_TESTS)
 
-# Print registered SQL test files in execution order
-test-list:
-	@printf "%s\n" $(TESTS)
+test-all: test-core test-integration test-performance