KKarthik Parameshwara13h ago · 7 min readThe SQL engine was fast. The table was the slow part.I built Blinkql, an open-source SQL workbench that runs in the browser. You open a CSV, Parquet, JSON or Excel file, write SQL and get results. The engine runs inside the tab, so the file is never uplkarthikparameshwara.hashnode.dev
AAbolfazl Mohajeri10h ago · 14 min readHow Does PostgreSQL Decide How to Execute a Query?When you send a SQL query to a database, have you ever wondered what actually happens behind the scenes? Consider the following query: SELECT * FROM orders WHERE user_id = 123 ORDER BY created_at DESCblog.abolfazlmohajeri.ir
PPipeline Whiteboard8h ago · 10 min readCDC Deletes, Tombstones and the Idempotent MERGEOrder 1042 was deleted at 14:10. At 15:00 it's back in the warehouse, marked shipped. Nobody re-created it. A retried batch did. This is Part 4 of CDC in Production. In Part 3 we caught silent data lopipelinewhiteboard.hashnode.dev
ZZyVOP18h ago · 10 min readPostgres Performance Basics: Reading EXPLAIN Output and Fixing Slow QueriesA slow query is a guess until you see its plan. Postgres will tell you exactly how it intends to run a query and, with one extra keyword, how the run actually went. Learning to read that output is oneblog.zyvop.com
UUsman Khan1d ago · 8 min readForeign Key Cascade Deletes: Un-Indexed FKs, Slow Cascades, and Lock Contention in PostgreSQLRunning a DELETE on a parent entity with ON DELETE CASCADE feels like clean relational cleanup. But if any child or grandchild table in the dependency chain lacks an index on its foreign key column, P12MActousman.hashnode.dev
TThyne Ventures1d ago · 2 min readIs your Snowflake warehouse queueing? One read-only query to checkSlow Snowflake dashboards aren't always slow queries. Often the query runs in two seconds but waits twenty in line because the warehouse is full. Here's a read-only query that shows which warehouses q1thyneventures.hashnode.dev
SSina Rezaei1d ago · 4 min readThe SQL NOT IN Trap: When NULL Quietly Breaks Your QueryI've seen SQL bugs that are easy to miss because nothing actually crashes. The query runs, the database returns a result, and the code moves on. You only notice something is wrong when a cleanup job ssinarezaei.hashnode.dev
Ccarrierlookup1d ago · 5 min readStandardizing Telephony Identifiers for Cross-System Data ReconciliationData reconciliation across disparate systems often founders on a seemingly trivial hurdle: the inconsistent representation of telephony identifiers. When a backend service collects phone numbers from carrierlookup.hashnode.dev
DDoogal Simpson3d ago · 5 min readSQL NOT IN vs NOT EXISTS: Handling NULL Values SafelyQuick Answer: In SQL, using WHERE column NOT IN (SELECT ...) returns zero rows if the subquery contains a single NULL. This occurs because NOT IN expands to chained != operators joined by AND, and any54SVTdoogal.dev
VVictor Horlenko3d ago · 7 min readWhen AI Agents Execute SQL: A Framework for Controlled AutonomyFor the last few years, AI help with databases has followed a comfortable routine. You describe a requirement, the model writes the SQL, you read it, fix what looks off and decide whether to run it. T1ainsights.hashnode.dev
