Note: This code is untested Define a record for your refCursor return type, call it rec. For example: TYPE MyRec IS RECORD (col1 VARCHAR2(10), col2 VARCHAR2(20), …); –define the record rec MyRec; — instantiate the record Once you have the refcursor returned from your procedure, you can add the following code where your comments are … Read more
Normally they are to be avoided, but the feature is there for a reason and there are times to use them. I’d say 90+% of the cursors I’ve seen are not needed. If you are using them for CRUD operations, that can almost always be redone in a set-based fashion. I’ve often seen people use … Read more
From my experience this means that the query results are too large for the cursor’s window and it requests more memory. Most times this request is honored, but on low end devices it could throw exceptions. I don’t know the specifics of the app in question but you referred to a ListView. A ListView cannot … Read more
You have a variety of problems. First, why are you using your specific @@FETCH_STATUS values? It should just be @@FETCH_STATUS = 0. Second, you are not selecting your inner Cursor into anything. And I cannot think of any circumstance where you would select all fields in this way – spell them out! Here’s a sample … Read more
If you are using the default cursor, a MySQLdb.cursors.Cursor, the entire result set will be stored on the client side (i.e. in a Python list) by the time the cursor.execute() is completed. Therefore, even if you use for row in cursor: you will not be getting any reduction in memory footprint. The entire result set … Read more
EDIT – Query performance: As @NeilLunn pointed out in his comments, you should not be filtering the documents manually, but use .find(…) for that instead: db.snapshots.find({ roundedDate: { $exists: true }, stream: { $exists: true }, sid: { $exists: false } }) Also, using .bulkWrite(), available as from MongoDB 3.2, will be far way more … Read more
Django’s cursor class is just a wrapper around the underlying DB’s cursor, so the effect of leaving the cursor open is basically tied to the underlying DB driver. According to psycopg2’s (psycopg2 is DB driver Django uses for PostgreSQL DB’s) FAQ, their cursors are lightweight, but will cache the data being returned from queries you … Read more
Here’s a comparison between toArray() and cursors after a find() in the Node.js MongoDB driver. Common code: var MongoClient = require(‘mongodb’).MongoClient, assert = require(‘assert’); MongoClient.connect(‘mongodb://localhost:27017/crunchbase’, function (err, db) { assert.equal(err, null); console.log(‘Successfully connected to MongoDB.’); const query = { category_code: “biotech” }; // toArray() vs. cursor code goes here }); Here’s the toArray() code that … Read more
Cursor objects returned by database queries are positioned before the first entry, therefore iteration can be simplified to: while (cursor.moveToNext()) { // Extract data. } Reference from SQLiteDatabase.