STSCI: Truncation warning appears when results are not truncated

[bhilbert4]

When uing pyvo to search for JWST data, I'm running into a situation where I'm getting a warning that the results are truncated when it turns out that they aren't.

Here is the code I am using:

import pyvo as vo
instrument = 'miri'
proposal = 9233
STSCI_VO_URL = "https://mast.stsci.edu/vo-tap/api/v0.1/caom"
tap_service = vo.dal.TAPService(STSCI_VO_URL)
tap_results = tap_service.search(f"select observationID from dbo.CaomObservation where collection='JWST' and insName like '{instrument.lower()}%' and prpID='{int(proposal)}'")

and the result is:

site-packages/pyvo/dal/query.py:404: DALOverflowWarning: Results truncated due to server limits. Consider setting a maxrec value.
  warn("Results truncated due to server limits. Consider "

len(tap_results)
102

If I repeat the query using a value of maxrec equal to 0 or to any value >102, I see the truncation warning and the results show the same list of 102 filenames. If I set maxrec to a value between 0 and 102, then the truncation warning does not show up, and the length of the resulting list is limited to maxrec entries, as expected. So it seems like the truncation warning should not be showing up in cases where maxrec > 102 (or 0)?

[msdemlei]

On Tue, Feb 24, 2026 at 11:09:16AM -0800, Bryan Hilbert wrote: expected. So it seems like the truncation warning should not be showing up in cases where maxrec > 102 (or 0)?

Indeed it should not. But it doesn't seem that that's pyvo's fault. Indeed, the service puts in a <INFO name="QUERY_STATUS" value="OVERFLOW"/> while apparently not overflowing at all. @tsdower, could you try to figure out what's going on?

[tsdower]

Hello! Unfortunately this bug popped up recently with MAST's major refactor of some TAP components for full ADQL 2.1 support. Apologies for the annoyance and thanks for reporting it; we are aware of the issue and will be working on it shortly (but decided not to roll back feature support in order to address it). I'll make a note to report progress here.