# Documentation of cholesky() and allocations

**URL:** https://discourse.julialang.org/t/documentation-of-cholesky-and-allocations/137927
**Category:** Offtopic
**Tags:** cholesky
**Created:** [July 3, 2026, 7:04pm UTC](https://discourse.julialang.org/t/documentation-of-cholesky-and-allocations/137927 "2026-07-03T19:04:04Z")
**Posts on this page:** 1
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### Author: ![stevengj](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/stevengj/32/71_2.png) [@stevengj](https://discourse.julialang.org/u/stevengj)
#### Post date: [July 4, 2026, 12:02am UTC](https://discourse.julialang.org/t/documentation-of-cholesky-and-allocations/137927/4 "2026-07-04T00:02:03Z")

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> [@Boris](#):
>
> I translated it to my code but didn’t see much difference between me using the C.L directly and using the object.

Using the object with C \setminus b is equivalent to U \setminus L \setminus b, not to just L \setminus b. That being said, there is an issue (hopefully to be resolved soon) where the Cholesky-object `ldiv!` is currently slower than it needs to be — see [Ldiv for Cholesky is slower than two substitutions - #6 by danielwe](https://discourse.julialang.org/t/ldiv-for-cholesky-is-slower-than-two-substitutions/130092/6) and [Triangular solve and inversions have poor performance · Issue #1405 · JuliaLang/LinearAlgebra.jl · GitHub](https://github.com/JuliaLang/LinearAlgebra.jl/issues/1405)

PS. I would generally wrap `C.U` in an `UpperTriangular` object to make sure that Julia exploits its structure, although in practice `ldiv!` checks for this.

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