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dbt🟡IntermediateHow incremental dbt models actually write: unique_key as merge grain, is_incremental filters, lookback windows, and the late-arrival cases that silently drop rows.
Snowflake🟡IntermediateHow Dynamic Tables actually refresh: TARGET_LAG, the warehouse that pays for it, streams vs DT, and why I still keep dbt for gold.
Snowflake🟡IntermediateWhat a micropartition is, how clustering and sargable filters prune, why wrapping columns and SELECT * blow the scan, and how to read partitions_scanned.
Snowflake🟡IntermediateCREATE … CLONE shares micropartitions until someone writes. How storage grows, how to clone at a timestamp, how I use clones in CI, and why I never mutate gold through a clone.
Trino🟢BeginnerTrino stores nothing. A federated SELECT * on prod Postgres is a database incident. Use Iceberg for the lake, and keep interactive SQL off OLTP.
Snowflake🟡IntermediateHow to use Cortex LLM functions inside pipelines — COMPLETE, CLASSIFY, EMBED — with cost controls, schema checks, retries, and a warehouse-native RAG shape.
Snowflake🟡IntermediateA practical guide to Snowflake Time Travel and Fail-safe: retention, UNDROP, cloning at a timestamp, storage cost, and a restore runbook you can test.
SQL🟡IntermediateDeduplication, running totals, sessionization, period-over-period comparisons, and top-N per group — plus frames, pitfalls, and live playground queries.
DuckDB🟡IntermediateWhy DuckDB replaced pandas in many pipelines: query Parquet and CSV files directly with SQL, at speeds that embarrass much bigger tools.
BigQuery🟡IntermediateBigQuery charges by bytes scanned. Learn how partitioning and clustering cut scan costs by 90%+, and the query patterns that silently bypass them.
Snowflake🟡IntermediateWarehouse sizing, auto-suspend, clustering, ACCOUNT_USAGE queries, and resource monitors — estimate the bill from usage before you change prod.
dbt🟢BeginnerSet up a dbt project from scratch: staging models, marts, tests, and documentation — with the project structure conventions used by real teams.
Data Modeling🟡IntermediateWorking SQL for every SCD type, the point-in-time join that most Type 2 implementations get wrong, and an honest account of which types are worth the maintenance.
Data Modeling🟡IntermediateJoins are not the expense they were in 2015. Here is what a wide denormalized table really costs in storage, rebuild time, and history, and the hybrid I ship instead of picking a side.
SQL🟡IntermediateDISTINCT, GROUP BY, ROW_NUMBER, QUALIFY, MERGE, and stream-side dedup compared on cost and semantics, plus how to pick the survivor row deterministically.
SQL🟡IntermediateHow WITH RECURSIVE actually executes, patterns for hierarchy traversal and BOM explosion, and the cycle guards that keep a bad edge from running forever.
SQL🟡IntermediateConditional aggregation, native PIVOT syntax, unpivoting wide tables, and how to handle dynamic categories without generating SQL at runtime.
dbt🟡IntermediateChoosing between check and timestamp snapshot strategies, what happens when a snapshot run is missed, and the cases where a hand-rolled SCD2 model beats dbt snapshot.
SQL🟡IntermediateWhat actually happens to a CTE in Postgres, Snowflake, and BigQuery, when it blocks predicate pushdown, and when referencing it twice costs you two scans.
AI & GenAI🟡IntermediateThe failure modes that only show up after launch — join paths, metric drift, runaway cost — and the semantic layer, constrained generation, and eval harness that make text-to-SQL survivable.
SQL🟡IntermediateHow window frames actually evaluate, why RANGE and ROWS give different answers on ties, and six window patterns that delete self-joins from your models.
SQL🟡IntermediateThe join fan-out failure class: grain checks before and after every join, EXISTS for semi-joins, anti-joins done right, and the postmortem pattern.
SQL🟡IntermediateFive SQL habits that scan more than they should: SELECT *, functions on filter columns, DISTINCT as a bug fix, OR-joins, and per-row UDF calls.
