Question about performance of dataset with large blobs in combination with deferredblobread
Posted: Mon 12 Nov 2018 14:24
I have a dataset which includes large blobfields. When fetching this data with a pgquery it takes a lot of time for the pgquery to open. While monitoring my network activity as the query was opening i noticed a rather high peak. It looks like all the data in the blobs is being retrieved from the server.
I noticed two properties that seem to affect this behaviour, DeferredBlobRead and CacheBlobs. The description of deferredblobread especially seems to describe the behaviour i would want, where blobfield data is only being retreived from the server once explicitely requested. When testing out these properties however, I noticed no change in the performance nor the network activity.
Am I right in thinking that deferredblobread = true should stop blobs being retreived from server in the pgquery.open? If so then am I using it wrong? I set the property on the the pgquery object before the open. If that's not what deferredblobread does is there some other way to do what I want to do?
I noticed two properties that seem to affect this behaviour, DeferredBlobRead and CacheBlobs. The description of deferredblobread especially seems to describe the behaviour i would want, where blobfield data is only being retreived from the server once explicitely requested. When testing out these properties however, I noticed no change in the performance nor the network activity.
Am I right in thinking that deferredblobread = true should stop blobs being retreived from server in the pgquery.open? If so then am I using it wrong? I set the property on the the pgquery object before the open. If that's not what deferredblobread does is there some other way to do what I want to do?