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Drop 31 unused indexes consuming 19.2 GiB #5

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179 changes: 179 additions & 0 deletions goodvibes/shop/migrations/0004_drop_unused_indexes.py
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Original file line number Diff line number Diff line change
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# Generated migration to drop unused indexes
# Issue: https://console.postgres.ai/goodvibes-ai/issues/019b3336-fb12-7072-b792-3233ffbcd699
#
# This migration drops 31 unused indexes consuming 19.2 GiB as identified by
# postgres.ai index analysis over 36 days of statistics.
#
# IMPORTANT NOTES:
# - All DROP INDEX operations use CONCURRENTLY to avoid blocking writes
# - This migration is non-atomic (atomic = False) because DROP INDEX CONCURRENTLY
# cannot run inside a transaction block
# - The reverse migration recreates indexes with CONCURRENTLY as well
# - If you need to test the impact before dropping, consider using HypoPG:
# SELECT hypopg_hide_index('schema.index_name'); to simulate removal
# - Alternative soft-drop: UPDATE pg_index SET indisvalid = false WHERE indexrelid = 'idx_name'::regclass;
# (requires superuser, index still maintained but ignored by planner)

from django.db import migrations
from django.contrib.postgres.operations import RemoveIndexConcurrently


class Migration(migrations.Migration):
# CONCURRENTLY operations cannot run in a transaction
atomic = False

dependencies = [
("shop", "0003_remove_orderitem_idx_orderitem_order_only_2"),
]

operations = [
# ============================================================
# Product indexes (4 explicit + 1 auto-generated _like index)
# ============================================================
RemoveIndexConcurrently(
model_name="product",
name="idx_product_sku_nonunique",
),
RemoveIndexConcurrently(
model_name="product",
name="idx_product_is_active",
),
RemoveIndexConcurrently(
model_name="product",
name="idx_product_name_plain",
),
RemoveIndexConcurrently(
model_name="product",
name="idx_product_name_lower",
),
# Django auto-generated _like index for varchar pattern ops
migrations.RunSQL(
sql="DROP INDEX CONCURRENTLY IF EXISTS shop_product_sku_20049d15_like;",
reverse_sql="CREATE INDEX CONCURRENTLY shop_product_sku_20049d15_like ON shop_product (sku varchar_pattern_ops);",
),
# ============================================================
# Customer indexes (2 explicit + 1 auto-generated _like index)
# ============================================================
RemoveIndexConcurrently(
model_name="customer",
name="idx_customer_email_plain",
),
RemoveIndexConcurrently(
model_name="customer",
name="idx_customer_email_lower",
),
# Django auto-generated _like index for varchar pattern ops
migrations.RunSQL(
sql="DROP INDEX CONCURRENTLY IF EXISTS shop_customer_email_d3fdf104_like;",
reverse_sql="CREATE INDEX CONCURRENTLY shop_customer_email_d3fdf104_like ON shop_customer (email varchar_pattern_ops);",
),
# ============================================================
# Order indexes (5 explicit + 1 auto-generated FK index)
# ============================================================
RemoveIndexConcurrently(
model_name="order",
name="idx_order_customer_created_at",
),
RemoveIndexConcurrently(
model_name="order",
name="idx_order_customer_only",
),
RemoveIndexConcurrently(
model_name="order",
name="idx_order_cancelled_full",
),
RemoveIndexConcurrently(
model_name="order",
name="idx_order_cust_inc_created",
),
RemoveIndexConcurrently(
model_name="order",
name="idx_order_cancelled_partial",
),
# Django auto-generated FK index
migrations.RunSQL(
sql="DROP INDEX CONCURRENTLY IF EXISTS shop_order_customer_id_f638df20;",
reverse_sql="CREATE INDEX CONCURRENTLY shop_order_customer_id_f638df20 ON shop_order (customer_id);",
),
# ============================================================
# OrderItem indexes (3 explicit + 2 auto-generated FK indexes)
# ============================================================
RemoveIndexConcurrently(
model_name="orderitem",
name="idx_orderitem_order_product",
),
RemoveIndexConcurrently(
model_name="orderitem",
name="idx_oi_prod_order_bad",
),
RemoveIndexConcurrently(
model_name="orderitem",
name="idx_orderitem_order_only",
),
# Django auto-generated FK indexes
migrations.RunSQL(
sql="DROP INDEX CONCURRENTLY IF EXISTS shop_orderitem_order_id_2f1b00cf;",
reverse_sql="CREATE INDEX CONCURRENTLY shop_orderitem_order_id_2f1b00cf ON shop_orderitem (order_id);",
),
migrations.RunSQL(
sql="DROP INDEX CONCURRENTLY IF EXISTS shop_orderitem_product_id_48153f22;",
reverse_sql="CREATE INDEX CONCURRENTLY shop_orderitem_product_id_48153f22 ON shop_orderitem (product_id);",
),
# ============================================================
# Non-Django managed tables (raw SQL required)
# These tables exist in the database but are not managed by Django models
# ============================================================
# orders table (4 indexes)
migrations.RunSQL(
sql="DROP INDEX CONCURRENTLY IF EXISTS orders_customer_created_idx;",
reverse_sql="CREATE INDEX CONCURRENTLY orders_customer_created_idx ON orders (customer_id, created_at);",
),
migrations.RunSQL(
sql="DROP INDEX CONCURRENTLY IF EXISTS orders_customer_idx;",
reverse_sql="CREATE INDEX CONCURRENTLY orders_customer_idx ON orders (customer_id);",
),
migrations.RunSQL(
sql="DROP INDEX CONCURRENTLY IF EXISTS orders_status_city_idx;",
reverse_sql="CREATE INDEX CONCURRENTLY orders_status_city_idx ON orders (status, city);",
),
migrations.RunSQL(
sql="DROP INDEX CONCURRENTLY IF EXISTS orders_status_idx;",
reverse_sql="CREATE INDEX CONCURRENTLY orders_status_idx ON orders (status);",
),
# order_items table (2 indexes)
migrations.RunSQL(
sql="DROP INDEX CONCURRENTLY IF EXISTS order_items_order_sku_idx;",
reverse_sql="CREATE INDEX CONCURRENTLY order_items_order_sku_idx ON order_items (order_id, sku);",
),
migrations.RunSQL(
sql="DROP INDEX CONCURRENTLY IF EXISTS order_items_sku_idx;",
reverse_sql="CREATE INDEX CONCURRENTLY order_items_sku_idx ON order_items (sku);",
),
# order_item_events table (3 indexes)
migrations.RunSQL(
sql="DROP INDEX CONCURRENTLY IF EXISTS order_item_events_updated_at_idx;",
reverse_sql="CREATE INDEX CONCURRENTLY order_item_events_updated_at_idx ON order_item_events (updated_at);",
),
migrations.RunSQL(
sql="DROP INDEX CONCURRENTLY IF EXISTS order_item_events_order_id_idx;",
reverse_sql="CREATE INDEX CONCURRENTLY order_item_events_order_id_idx ON order_item_events (order_id);",
),
migrations.RunSQL(
sql="DROP INDEX CONCURRENTLY IF EXISTS order_item_events_customer_id_idx;",
reverse_sql="CREATE INDEX CONCURRENTLY order_item_events_customer_id_idx ON order_item_events (customer_id);",
),
# payments table (3 indexes)
migrations.RunSQL(
sql="DROP INDEX CONCURRENTLY IF EXISTS payments_provider_status_idx;",
reverse_sql="CREATE INDEX CONCURRENTLY payments_provider_status_idx ON payments (provider, status);",
),
migrations.RunSQL(
sql="DROP INDEX CONCURRENTLY IF EXISTS payments_status_idx;",
reverse_sql="CREATE INDEX CONCURRENTLY payments_status_idx ON payments (status);",
),
migrations.RunSQL(
sql="DROP INDEX CONCURRENTLY IF EXISTS payments_provider_idx;",
reverse_sql="CREATE INDEX CONCURRENTLY payments_provider_idx ON payments (provider);",
),
]

46 changes: 0 additions & 46 deletions goodvibes/shop/models.py
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from django.db import models
from django.db.models import Q
from django.db.models.functions import Lower


class Product(models.Model):
Expand All @@ -10,66 +8,22 @@ class Product(models.Model):
is_active = models.BooleanField(default=True)
created_at = models.DateTimeField(auto_now_add=True)

class Meta:
indexes = [
# Redundant duplicate alongside the implicit unique index
models.Index(fields=["sku"], name="idx_product_sku_nonunique"),
# Low-selectivity index (often not used)
models.Index(fields=["is_active"], name="idx_product_is_active"),
# Plain vs functional (we'll bias workload to use the functional)
models.Index(fields=["name"], name="idx_product_name_plain"),
models.Index(Lower("name"), name="idx_product_name_lower"),
]


class Customer(models.Model):
email = models.EmailField(unique=True)
full_name = models.CharField(max_length=255)
created_at = models.DateTimeField(auto_now_add=True)

class Meta:
indexes = [
# Redundant duplicate alongside the implicit unique index
models.Index(fields=["email"], name="idx_customer_email_plain"),
# Functional index used by case-insensitive lookups
models.Index(Lower("email"), name="idx_customer_email_lower"),
]


class Order(models.Model):
customer = models.ForeignKey(Customer, on_delete=models.CASCADE)
created_at = models.DateTimeField(auto_now_add=True)
cancelled_at = models.DateTimeField(null=True, blank=True)

class Meta:
indexes = [
# Composite index used by our hot path queries
models.Index(fields=["customer", "created_at"], name="idx_order_customer_created_at"),
# Shadowed by the composite index for most queries
models.Index(fields=["customer"], name="idx_order_customer_only"),
# Full index vs partial; workload favors partial
models.Index(fields=["cancelled_at"], name="idx_order_cancelled_full"),
# INCLUDE variant (redundant coverage given the composite)
models.Index(fields=["customer"], name="idx_order_cust_inc_created", include=["created_at"]),
models.Index(
fields=["cancelled_at"], name="idx_order_cancelled_partial", condition=Q(cancelled_at__isnull=True)
),
]


class OrderItem(models.Model):
order = models.ForeignKey(Order, on_delete=models.CASCADE)
product = models.ForeignKey(Product, on_delete=models.CASCADE)
quantity = models.PositiveIntegerField(default=1)

class Meta:
indexes = [
# Used by joins/filters that start with order
models.Index(fields=["order", "product"], name="idx_orderitem_order_product"),
# Reversed order (likely unused)
models.Index(fields=["product", "order"], name="idx_oi_prod_order_bad"),
# Single-column shadowed by composite
models.Index(fields=["order"], name="idx_orderitem_order_only"),
]