I am searching distance between point and nearest road (OSM data). I wrote next SQL request:

SELECT osm_id, st_astext(geometry),  ST_DISTANCE(geometry::geography, ST_SetSRID(ST_POINT(37.72308, 55.47957), 4326), true) AS dist, roads.geometry::geography <-> ST_SetSRID(ST_MakePoint(37.72308, 55.47957),4326)  as op_dist
FROM roads ORDER BY ST_SetSRID(roads.geometry, 4326)::geography <-> ST_SetSRID(ST_MakePoint(37.72308, 55.47957),4326) ASC LIMIT 1;

result dist is: 27.830223659

I added this data to the QGIS and calculated distance with the meter instrument and it's show that the distance is 34.3 meters.

What can be wrong and why?

I am searching distance between point and nearest road (OSM data). I wrote next SQL request:

SELECT osm_id, st_astext(geometry),  ST_DISTANCE(geometry::geography, ST_SetSRID(ST_POINT(37.72308, 55.47957), 4326), true) AS dist, roads.geometry::geography <-> ST_SetSRID(ST_MakePoint(37.72308, 55.47957),4326)  as op_dist
FROM roads ORDER BY ST_SetSRID(roads.geometry, 4326)::geography <-> ST_SetSRID(ST_MakePoint(37.72308, 55.47957),4326) ASC LIMIT 1;

result dist is: 27.830223659

I added this data to the QGIS and calculated distance with the meter instrument and it's show that the distance is 34.3 meters.

What can be wrong and why?

PostGIS 2.2