paleolimbot commented on issue #34319:
URL: https://github.com/apache/arrow/issues/34319#issuecomment-1462665299
A good workaround is probably just to use the `ParquetFileReader` directly:
``` r
library(arrow, warn.conflicts = FALSE)
#> Some features are not enabled in this build of Arrow. Run `arrow_info()`
for more information.
n_col <- 16000
many_cols <- rep(list(1L), n_col)
names(many_cols) <- paste0("col", seq_len(n_col))
many_cols <- as.data.frame(many_cols)
temp_parquet <- tempfile()
write_parquet(many_cols, temp_parquet)
system.time(read_parquet(temp_parquet, col_select = 1:200))
#> user system elapsed
#> 5.863 0.534 6.375
system.time({
reader <- ParquetFileReader$create(temp_parquet)
as.data.frame(reader$ReadTable(1:200))
})
#> user system elapsed
#> 0.220 0.007 0.207
```
Perhaps the best fix here is a docs fix to suggest that this is
possible/desirable? I would prefer that to adding more complexity to the
implementation.
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