# Append rows to a JuliaDB table on disk
**URL:** https://discourse.julialang.org/t/append-rows-to-a-juliadb-table-on-disk/44071
**Category:** General Usage
**Created:** [August 1, 2020, 5:03am UTC](https://discourse.julialang.org/t/append-rows-to-a-juliadb-table-on-disk/44071 "2020-08-01T05:03:53Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@robsmith11](https://discourse.julialang.org/u/robsmith11)
#### Post date: [August 1, 2020, 5:03am UTC](https://discourse.julialang.org/t/append-rows-to-a-juliadb-table-on-disk/44071/1 "2020-08-01T05:03:53Z")
I have streaming structured data that I’d like to write to disk either row-by-row or with a small amount of buffering.
Is JuliaDB appropriate for this? I ultimately will want to do some data manipulation on the resulting tables using JuliaDB, so it would be nice if I could keep everything in one format. After a brief search, I couldn’t find a way to append to an on-disk table, only rewrite the entire table, which would be extremely inefficient (incoming data will arrive at around 1-2MB/s).
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### Author:  [@gkappler](https://discourse.julialang.org/u/gkappler)
#### Post date: [August 4, 2020, 9:33am UTC](https://discourse.julialang.org/t/append-rows-to-a-juliadb-table-on-disk/44071/2 "2020-08-04T09:33:38Z")
I refactored the JuliaDB load code a bit ([https://github.com/JuliaData/JuliaDB.jl/pull/365](https://github.com/JuliaData/JuliaDB.jl/pull/365)) to
1. read a chunk in a `nd::NDSparse` and then
2. merge! with `dnd::JuliaDB.DNDSparse`:
```julia
merge!(dnd, nd; output=x.output)
```
Performance is really good on my SSD laptop, at least writing about 1-2 mio rows/sec with 3 Int64 columns.
If chunks are small, many chunk files will be created, which I `rechunk!` in a finalizing compression.
Also, PR [https://github.com/JuliaData/JuliaDB.jl/pull/288](https://github.com/JuliaData/JuliaDB.jl/pull/288) is discussing a csv approach.