[I] [CPP] Table query returns 0 rows when the time range starts in a device's second chunk [tsfile]

["fl0-m (via GitHub)" <gi...@apache.org>]

fl0-m opened a new issue, #972:
URL: https://github.com/apache/tsfile/issues/972

   **Version:** apache/tsfile `cpp`, commit 7ca2e79 (and `develop` 83fe559, same code). Files written by IoTDB 2.0.11 (table model, aligned).
   
   **What happens.** `TsFileSeriesScanIterator::init_chunk_reader_multi` loads the device's FIRST chunk without looking at the time filter. The first `get_next` then calls `get_next_page` on that chunk; when none of its rows is in the time range it returns `E_OK` with an **empty** TsBlock, and `get_next` returns that as a success. The table reader treats an empty block as the end of the series, so a query whose time range starts in a later chunk of the file returns 0 rows.
   
   **Reproduction.** Any IoTDB file whose device has ≥ 2 chunks (e.g. after one inner compaction). Query the table with `start_time` at the middle of the device's time range: 0 rows are returned; without a time filter, or with a start inside the first chunk, the rows are there. On a real file (one device, 2 chunks, 23,751 rows) a start at 50 % of the range returned 0 of 11,666 rows and at 75 % 0 of 5,809.
   
   **Fix that works for us** (in `TsFileSeriesScanIterator::get_next`, after the `E_NO_MORE_DATA` with rows check):
   ```cpp
   if (IS_SUCC(ret) && ret_tsblock != nullptr && ret_tsblock->get_row_count() == 0) {
       if (chunk_reader_->has_more_data()) continue;          // next page of this chunk
       if (has_next_chunk()) { force_load_next_chunk = true; continue; }  // next chunk
       return common::E_NO_MORE_DATA;
   }
   ```
   With it, 1,490 of 1,490 time windows over 60 real files equalled a read without a time filter (count and sum).
   


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Re: [I] [CPP] Table query returns 0 rows when the time range starts in a device's second chunk [tsfile]

[Alan Chuang <al...@gmail.com>]

Thanks for the issue and the fix example. We have applied the patch.

On Thu, Oct 8, 2026 at 11:57 AM ColinLeeo (via GitHub) <gi...@apache.org>
wrote:

>
> ColinLeeo closed issue #972: [CPP] Table query returns 0 rows when the
> time range starts in a device's second chunk
> URL: https://github.com/apache/tsfile/issues/972
>
>
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> This is an automated message from the Apache Git Service.
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Re: [I] [CPP] Table query returns 0 rows when the time range starts in a device's second chunk [tsfile]

["ColinLeeo (via GitHub)" <gi...@apache.org>]

ColinLeeo commented on issue #972:
URL: https://github.com/apache/tsfile/issues/972#issuecomment-6051879355

   Thanks for your issue and fix example.  👍 


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Re: [I] [CPP] Table query returns 0 rows when the time range starts in a device's second chunk [tsfile]

["ColinLeeo (via GitHub)" <gi...@apache.org>]

ColinLeeo closed issue #972: [CPP] Table query returns 0 rows when the time range starts in a device's second chunk
URL: https://github.com/apache/tsfile/issues/972


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