Witold swierzy patch 133

data-platform/autonomous-ai-database/autonomous-ai-json/oracle-api-for-mongodb-demos/NodeJS/hr/03_expr.js

@@ -11,34 +11,15 @@ async function expr() {
         await utils.prepareSchema(db);
         console.log("Database schema prepared.");
 
-        if (oracle_api)
+        if (oracle_api) {
             console.log("You are connected to an Oracle MongoDB API service.");
+            console.log("This version of API supports $expr operator");
+        }
         else
             console.log("You are connected to a native MongoDB database.");
 
-        if (!oracle_api) {
-           console.log("You are using native MongoDB service. $expr operator is fully supported.");
-           emps = db.collection("EMPLOYEES_COL").find({$expr: {$lt: ["$manager_id","$_id"]}});
-        }
-        else {
-           try {
-                console.log("Query using $expr operator.");
-                console.log("db.EMPLOYEES_COL.find({$expr: {$lt: ['$manager_id','$_id']}})")
-                emps = db.collection("EMPLOYEES_COL").find({$expr: {$lt: ["$manager_id","$_id"]}});
-                for await (emp of emps) {
-                    console.log(emp.last_name + " " + emp.first_name);         
-                }  
-           }
-           catch (e) {
-                console.log("You are using Oracle MongoDB API. $epr operator has limited support.");
-                console.error(e);
-           }
-           console.log("You are using Oracle MongoDB API. There is need to use $sql operator instead of $expr.");
-           console.log("Query : select c.DATA from EMPLOYEES_COL c where c.DATA.manager_id < c.DATA.'_id'");
-           emps = db.aggregate([{ $sql: 'select c.DATA from EMPLOYEES_COL c where c.DATA.manager_id < c.DATA."_id"' }] ); 
-           console.log("Execution plan : ");
-           await utils.displaySQLExecutionPlan(db,'select c.DATA from EMPLOYEES_COL c where c.DATA.manager_id < c.DATA."_id"');
-        }
+        emps = db.collection("EMPLOYEES_COL").find({$expr: {$lt: ["$manager_id","$_id"]}});
+
         for await (emp of emps)
             console.log(emp.last_name + " " + emp.first_name); 
     }   

data-platform/autonomous-ai-database/autonomous-ai-json/oracle-api-for-mongodb-demos/NodeJS/hr/06_partial_indexes.js

@@ -16,51 +16,23 @@ async function partial_indexes() {
             console.log("Connection to an Oracle MongoDB API instance created.");
         else
             console.log("Connection to a native MongoDB instance created.");
-
-        if (!oracle_api) {
-            console.log("You are connected to a native MongoDB. Partial indexes are natively supported.");
-            numOfIndexes = (await db.collection("EMPLOYEES_COL").aggregate([{$indexStats:{}}]).toArray()).length;
-            console.log("Number of indexes on EMPLOYEES_COL collections BEFORE INDEXING : "+numOfIndexes);
+        numOfIndexes = (await db.collection("EMPLOYEES_COL").aggregate([{$indexStats:{}}]).toArray()).length;
+        console.log("Number of indexes on EMPLOYEES_COL collections BEFORE INDEXING : "+numOfIndexes);
 
-            await db.collection("EMPLOYEES_COL").createIndex( { salary: 1, last_name: 1 },
+        await db.collection("EMPLOYEES_COL").createIndex( { salary: 1, last_name: 1 },
                                                               { partialFilterExpression : { salary: { $lt: 8000 } } } );
 
-            numOfIndexes = (await db.collection("EMPLOYEES_COL").aggregate([{$indexStats:{}}]).toArray()).length;
-            console.log("Index created succesfully."); 
-            console.log("Number of indexes on EMPLOYEES_COL collections AFTER INDEXING : "+numOfIndexes);
-
-            console.log("Execution plan, which uses partial index.");
-            console.log("Query: db.EMPLOYEES_COL.find({salary:4200})");
-            emps = db.collection("EMPLOYEES_COL").find({salary:4200});
-            console.log("Results : ");
-            for await (emp of emps)
-                console.log(emp._id+" "+emp.last_name+" "+emp.salary);
-            await utils.displayExecutionPlan(db,"EMPLOYEES_COL",{SALARY:42000},"salary_1_last_name_1");
-
-        }
-        else {
-            console.log("You are using Oracle MongoDB API. To create a partial index you need to use:"); 
-            console.log("1. $sql operator");
-            console.log("2. Function-based Indexes.");
-
-            result = db.aggregate([{ $sql: "select * from user_indexes where index_type <> 'LOB' and table_name = 'EMPLOYEES_COL'" }] )
-            numOfIndexes = (await result.toArray()).length;
-            console.log("Number of indexes on EMPLOYEES_COL collections BEFORE INDEXING : "+numOfIndexes);
-
-            result = db.aggregate([ {$sql: {statement: "CREATE INDEX EMPLOYEES_SALARY_IDX on EMPLOYEES_COL(partial_value(DATA))"}}]);
-            for await (res of result);
-
-            result = db.aggregate([{ $sql: "select * from user_indexes where index_type <> 'LOB' and table_name = 'EMPLOYEES_COL'" }]);
-            numOfIndexes = (await result.toArray()).length;
-            console.log("Number of indexes on EMPLOYEES_COL collections AFTER INDEXING : "+numOfIndexes);  
-            console.log("Execution plan, which uses partial index.");
-            console.log("Query : select c.data from employees_col c where partial_value(data)=4200");
-            emps = db.aggregate([{ $sql: "select c.data from employees_col c where partial_value(data)=4200" }] );
-            console.log("Results : ");
-            for await (emp of emps)
-                console.log(emp._id+" "+emp.last_name+" "+emp.salary);
-            await utils.displaySQLExecutionPlan(db,"select c.data from employees_col c where partial_value(data)=4200");
-        } 
+        numOfIndexes = (await db.collection("EMPLOYEES_COL").aggregate([{$indexStats:{}}]).toArray()).length;
+        console.log("Index created succesfully."); 
+        console.log("Number of indexes on EMPLOYEES_COL collections AFTER INDEXING : "+numOfIndexes);
+
+        console.log("Execution plan, which uses partial index.");
+        console.log("Query: db.EMPLOYEES_COL.find({salary:4200})");
+        emps = db.collection("EMPLOYEES_COL").find({salary:4200});
+        console.log("Results : ");
+        for await (emp of emps)
+            console.log(emp._id+" "+emp.last_name+" "+emp.salary);
+        await utils.displayExecutionPlan(db,"EMPLOYEES_COL",{SALARY:42000},"salary_1_last_name_1");
     }   
     catch (e) {
         console.error(e);

data-platform/autonomous-ai-database/autonomous-ai-json/oracle-api-for-mongodb-demos/NodeJS/hr/10_aggregations.js

@@ -30,10 +30,10 @@ async function aggregations() {
         result = await db.collection("EMPLOYEES_COL").aggregate([
             { $group : { _id : '$department_id', avgsalary : { $avg : "$salary" } } }
         ]).explain();
-        if (!oracle_api)
-            console.log(result.queryPlanner.winningPlan);
-        else
-            console.log(result.stages[0].$sql);
+        //if (!oracle_api)
+        //    console.log(result.queryPlanner.winningPlan);
+        //else
+        //    console.log(result.stages[0].$sql);
     }   
     catch (e) {
         console.error(e);

data-platform/autonomous-ai-database/autonomous-ai-json/oracle-api-for-mongodb-demos/NodeJS/hr/12_change_streams_consumer.js

@@ -0,0 +1,51 @@
+const utils         = require("./00_utils");
+const {MongoClient} = require("mongodb");
+
+async function change_streams_consumer() {      
+    let client        = new MongoClient(process.env.MONGO_URI);
+    let db            = client.db();
+    let session       = client.startSession();
+    let oracle_api    = !(await utils.isNativeMongoDB(db));  
+    let db_version    = await utils.getDBVersion(db);
+
+    try {           
+        console.log("Preparing the database schema.");
+        await utils.prepareSchema(db)
+        console.log("Database schema prepared.");
+
+        if (oracle_api)
+            console.log("You are connected to an Oracle MongoDB API. ");
+        else 
+            console.log("You are connected to a native MongoDB instance.");
+
+        console.log("Enabling changeStreams for DEPARTMENTS_COL collection");
+
+        var commandDoc = {collMod: "DEPARTMENTS_COL",preview:true, enableChangeStream:{preAndPost:true}};
+
+        var results = await db.command(commandDoc);
+
+        console.log(results);
+
+        console.log("changeStreams enabled");
+        console.log("Starting to consume events produced by producer's code");
+
+        const collection = db.collection("DEPARTMENTS_COL");
+
+        const changeStream = collection.watch();
+        // start listen to changes
+        console.log("Starting to consume events produced by producer's code");
+
+        for (var i=0; i < 25; i++) {
+            console.log(await changeStream.next()); 
+        }
+    }   
+    catch (e) {
+        console.error(e);
+    }  
+    finally {
+        await client.close();
+        console.log("Disconnected from database.");
+    }
+}
+
+change_streams_consumer().catch(console.error);

data-platform/autonomous-ai-database/autonomous-ai-json/oracle-api-for-mongodb-demos/NodeJS/hr/12_change_streams_producer.js

@@ -0,0 +1,3 @@
+// this code needs to be executed in mongosh
+ for (var i=200; i < 225; i++) 
+    db.DEPARTMENTS_COL.insertOne({"_id" : i, "department_name" : "New Department #"+i})

data-platform/autonomous-ai-database/autonomous-ai-json/oracle-api-for-mongodb-demos/NodeJS/hr/13_bsonSize.js

@@ -0,0 +1,35 @@
+const utils         = require("./00_utils");
+const {MongoClient} = require("mongodb");
+
+async function bsonSize() {      
+    let client        = new MongoClient(process.env.MONGO_URI);
+    let db            = client.db();
+    let session       = client.startSession();
+    let oracle_api    = !(await utils.isNativeMongoDB(db));  
+    let db_version    = await utils.getDBVersion(db);
+    try {
+        console.log("Preparing the database schema.");
+        await utils.prepareSchema(db);
+        console.log("Database schema prepared.");
+        result = await db.collection("EMPLOYEES_COL").aggregate([
+                {
+                    "$project": {
+                    "last_name": 1,
+                    "object_size": { $bsonSize: "$$ROOT" }
+                    }
+                }
+        ]);
+        console.log("Results : ");
+        for await (doc of result)
+            console.log(doc.last_name+" "+doc.object_size);
+    }   
+    catch (e) {
+        console.error(e);
+    }  
+    finally {
+        await client.close();
+        console.log("Disconnected from database.");
+    }
+}        
+
+bsonSize().catch(console.error);

data-platform/autonomous-ai-database/autonomous-ai-json/oracle-api-for-mongodb-demos/NodeJS/hr/14_lookup.js

@@ -0,0 +1,60 @@
+const utils         = require("./00_utils");
+const {MongoClient} = require("mongodb");
+
+async function lookup_example() {      
+    let client        = new MongoClient(process.env.MONGO_URI);
+    let db            = client.db();
+    let session       = client.startSession();
+    let oracle_api    = !(await utils.isNativeMongoDB(db));  
+    let db_version    = await utils.getDBVersion(db);
+    try {
+        console.log("Preparing the database schema.");
+        await utils.prepareSchema(db);
+        console.log("Database schema prepared.");
+        console.log("Simple lookup");
+        result = await db.collection("EMPLOYEES_COL").aggregate( [
+                {
+                    $lookup:
+                    {
+                        from: "EMPLOYEES_COL",
+                        localField: "_id",
+                        foreignField: "department_id",
+                        as: "EMPLOYEES"
+                    }
+                }
+        ] );
+        console.log("Results : ");
+        for await (doc of result)
+            console.log(doc);
+        console.log("Example with lookup, let and pipeline");
+        console.log("This example requires database version 23.26.2");
+        result = await db.collection("DEPARTMENTS_COL").aggregate( [
+        {
+            $lookup: {
+                from: "EMPLOYEES_COL",
+                let: { deptno : "$_id"},
+                pipeline: [ {
+                    $match: {
+                        $expr: {
+                            $eq: [ "$$deptno", "$department_id" ] 
+                        } 
+                    }
+                } ],
+                as: "matches"
+            }
+          }
+        ] );
+        console.log("Results : ");
+        for await (doc of result)
+            console.log(doc);
+    }   
+    catch (e) {
+        console.error(e);
+    }  
+    finally {
+        await client.close();
+        console.log("Disconnected from database.");
+    }
+}        
+
+lookup_example().catch(console.error);