[section_faiss_vector_index] Minor refactor removing unnecessary vars (…

…#309)

section_faiss_vector_index.go

@@ -146,17 +146,13 @@ func (v *faissVectorIndexSection) Merge(opaque map[int]resetable, segments []*Se
 				// remap the docID from the old segment to the new document nos.
 				// provided. furthermore, also drop the now-invalid doc nums
 				// of that segment
-				var vecIDNotDeleted bool // indicates if the vector ID was not deleted.
-				var newDocID uint64      // new docID in the new segment
 				if newDocNumsIn[segI][uint32(docID)] != docDropped {
-					newDocID = newDocNumsIn[segI][uint32(docID)]
-					vecIDNotDeleted = true
-				}
-				// if the remapped doc ID is valid, track it
-				// as part of vecs to be reconstructed (for larger indexes).
-				// this would account only the valid vector IDs, so the deleted
-				// ones won't be reconstructed in the final index.
-				if vecIDNotDeleted {
+					newDocID := newDocNumsIn[segI][uint32(docID)]
+
+					// if the remapped doc ID is valid, track it
+					// as part of vecs to be reconstructed (for larger indexes).
+					// this would account only the valid vector IDs, so the deleted
+					// ones won't be reconstructed in the final index.
 					vecToDocID[vecID] = newDocID
 					indexes[curIdx].vecIds = append(indexes[curIdx].vecIds, vecID)
 				}
@@ -250,11 +246,7 @@ func (v *vectorIndexOpaque) flushVectorIndex(indexBytes []byte, w *CountHashWrit
 
 	// write the vector index data
 	_, err = w.Write(indexBytes)
-	if err != nil {
-		return err
-	}
-
-	return nil
+	return err
 }
 
 // Divide the estimated nprobe with this value to optimize
@@ -379,7 +371,6 @@ func (v *vectorIndexOpaque) mergeAndWriteVectorIndexes(sbs []*SegmentBase,
 	// the reconstructed ones anymore and doing so will hold up memory which can
 	// be detrimental while creating indexes during introduction.
 	freeReconstructedIndexes(vecIndexes)
-	vecIndexes = nil
 
 	faissIndex, err := faiss.IndexFactory(dims, indexDescription, metric)
 	if err != nil {
@@ -414,20 +405,12 @@ func (v *vectorIndexOpaque) mergeAndWriteVectorIndexes(sbs []*SegmentBase,
 		return err
 	}
 
-	indexData = nil
-	finalVecIDs = nil
-	var mergedIndexBytes []byte
-	mergedIndexBytes, err = faiss.WriteIndexIntoBuffer(faissIndex)
-	if err != nil {
-		return err
-	}
-
-	err = v.flushVectorIndex(mergedIndexBytes, w)
+	mergedIndexBytes, err := faiss.WriteIndexIntoBuffer(faissIndex)
 	if err != nil {
 		return err
 	}
 
-	return nil
+	return v.flushVectorIndex(mergedIndexBytes, w)
 }
 
 // todo: can be parallelized.