#windowfunctions — Public Fediverse posts

Window ORDER BY NULLS FIRST - LAST?!

NULLS FIRST and NULLS LAST change window function results! The order of NULLs matters in window functions. This subtle difference will cause bugs!

#sql #sqltricks #windowfunctions #nullsfirst #nullslast #sqlweird #sqlquiz #codingchallenge #sqlshorts #sqlwtf #nullhandling #advancedsql

https://www.youtube.com/watch?v=TbQfBej6dis

ROW_NUMBER() OVER (ORDER BY NULL) Does WHAT?!

ROW_NUMBER with ORDER BY NULL creates non-deterministic ordering! All rows get random numbers. This breaks window functions! Watch!

#sql #sqltricks #database #sqltutorial #rownumber #windowfunctions #sqlquiz #codingchallenge #sqlshorts #sqlbugs #ordering #sqlwtf

https://www.youtube.com/watch?v=MVixOi9e8zE

#throwback Still using aggregates where window functions shine? 📈 Jan Suchánek explains analytical functions in PostgreSQL and shows how rewriting queries can drastically reduce response times. Practical examples and real performance gains.

▶️ Watch now! https://www.youtube.com/watch?v=cXIRGGD_TZ8&list=PL_m-TUcr7ZvnSBmPoxZvcB1lfy7C9eced&index=14

#PostgreSQL #PGDay #PPDD #SQL #WindowFunctions

LAG - LEAD Default Value Trap?!

LAG and LEAD have DEFAULT values! When there's no previous/next row, they return the default. This hidden parameter will surprise you!

#sql #sqltricks #lag #lead #defaultvalue #sqlweird #sqlquiz #codingchallenge #sqlshorts #sqlwtf #windowfunctions #advancedsql

https://www.youtube.com/watch?v=zGKaBIgNThU

Window PARTITION BY Changes Results?!

PARTITION BY creates separate windows! Each partition has its own running sum. This partitioning will change your aggregation results!

#sql #sqltricks #partitionby #windowfunctions #runningsum #sqlweird #sqlquiz #codingchallenge #sqlshorts #sqlwtf #advancedsql

https://www.youtube.com/watch?v=OdUmjf_ZbSU

NTH_VALUE Gets Specific Position?!

NTH_VALUE extracts the Nth value from window! It's like array indexing for window functions. This positional access will surprise you!

#sql #sqltricks #nthvalue #windowfunctions #positionalaccess #sqlweird #sqlquiz #codingchallenge #sqlshorts #sqlwtf #advancedsql

https://www.youtube.com/watch?v=6wNXQoiEg8Y

Window ROWS vs RANGE Frame Difference?!

ROWS and RANGE frames are COMPLETELY different! ROWS counts physical rows, RANGE groups by value. Same query, DIFFERENT results. This will confuse you!

#sql #sqltricks #windowfunctions #rowsvsrange #framespecification #sqlweird #sqlquiz #codingchallenge #sqlshorts #sqlwtf #advancedsql #database

https://www.youtube.com/watch?v=Gu3PDsCRO_w

Window Function SUM() With NULL Partition?!

Window functions with NULL partitions create chaos! SUM OVER (PARTITION BY NULL) behaves unexpectedly. This breaks analytics! Watch!

#sql #sqltricks #database #sqltutorial #windowfunctions #nullpartition #sqlquiz #codingchallenge #sqlshorts #sqlbugs #analytics #sqlwtf

https://www.youtube.com/watch?v=66BfdH3qLsg

PostgreSQL CTEs và Window Functions: Kỹ thuật truy vấn nâng cao. Tìm hiểu cách sử dụng CTEs (Common Table Expressions) và Window Functions trong PostgreSQL để viết các truy vấn phức tạp và hiệu quả hơn.

#PostgreSQL #Database #SQL #CTEs #WindowFunctions #LậpTrình #CơSởDữLiệu

https://www.reddit.com/r/programming/comments/1m4jprb/postgresql_ctes_window_functions_advanced_query/