# Error when optimizing Iceberg table with Merge-on-Read

**URL:** https://community.dremio.com/t/error-when-optimizing-iceberg-table-with-merge-on-read/12941
**Category:** Uncategorized
**Created:** [April 14, 2025, 9:15pm UTC](https://community.dremio.com/t/error-when-optimizing-iceberg-table-with-merge-on-read/12941 "2025-04-14T21:15:01Z")
**Posts on this page:** 1
**Page:** 1

<div class="post-metadata">

### Author: ![sgoldsmith](https://avatars.discourse-cdn.com/v4/letter/s/919ad9/32.png) [@sgoldsmith](https://community.dremio.com/u/sgoldsmith)
#### Post date: [April 14, 2025, 9:15pm UTC](https://community.dremio.com/t/error-when-optimizing-iceberg-table-with-merge-on-read/12941/1 "2025-04-14T21:15:02Z")

</div>

I am testing an iceberg table that has the table property write.delete.mode = merge-on-read but whenever I run OPTIMIZE TABLE I get the following Error:

```auto
      DATA_READ ERROR: Failed to read record batch with PositionalDeleteFilter

PositionalDeleteFilter start position 0
PositionalDeleteFilter end position -1
PositionalDeleteFilter current position 0
PositionalDeleteFilter total batches evaluated 0
PositionalDeleteFilter total rows evaluated 0
PositionalDeleteFilter total rows deleted 0
PositionalDeleteFilter rows evaluated last batch 0
PositionalDeleteFilter rows deleted last batch 0
File path /datastore/testtable/180288eb-d8eb-7925-8ad1-72aa7b9cc300/1094_2025_03_12T00_00/1094_TEST/2_1_223.parquet
Rowgroup index 0
SqlOperatorImpl TABLE_FUNCTION
Location 4:1:2
ErrorOrigin: EXECUTOR
[Error Id: f72d32ad-f878-4bcb-823f-ae8cbe74b52f on dm-stg1-drw3:0]

  (java.lang.IllegalStateException) Current row position should never be greater than next delete position. Positional delete files may be invalid with unsorted positions.

```