fix(tpcds): fix bugs in tpcds datagen script

[universalmind303]

No description provided.

[codspeed-hq]

CodSpeed Performance Report

Merging #3495 will degrade performances by 29.87%

_{Comparing universalmind303:fix-tpcds-datagen (061bde2) with main (c2abed8)}

Summary

⚡ 1 improvements
❌ 1 regressions
✅ 15 untouched benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	main	universalmind303:fix-tpcds-datagen	Change
❌	test_iter_rows_first_row[100 Small Files]	228.4 ms	325.7 ms	-29.87%
⚡	test_show[100 Small Files]	23.5 ms	15.7 ms	+49.54%

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 77.44%. Comparing base (3eeba09) to head (061bde2).
Report is 9 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3495      +/-   ##
==========================================
+ Coverage   77.38%   77.44%   +0.05%     
==========================================
  Files         699      702       +3     
  Lines       84971    85215     +244     
==========================================
+ Hits        65753    65991     +238     
- Misses      19218    19224       +6     

see 5 files with indirect coverage changes

[raunakab]

LGTM!