Updating docs and dgraph-js versions in examples (#116)

Signed-off-by: Prashant Shahi <[email protected]>

Author: prashant-shahi

README.md

@@ -169,6 +169,23 @@ try {
 }
 ```
 
+To create a read-only transaction, set `readOnly` boolean to `true` while calling
+`DgraphClient#newTxn()` method. Read-only transactions cannot contain mutations and
+trying to call `Txn#mutate()` or `Txn#commit()` will result in an error. Calling
+`Txn.Discard()` will be a no-op.
+
+You can optionally set the `bestEffort` boolean to `true`. This may yield improved
+latencies in read-bound workloads where linearizable reads are not strictly needed.
+
+```js
+const txn = dgraphClient.newTxn({
+  readOnly: true,
+  bestEffort: false
+});
+// ...
+const res = await txn.queryWithVars(query, vars);
+```
+
 ### Running a Mutation
 
 `Txn#mutate(Mutation)` runs a mutation. It takes in a `Mutation` object, which

examples/simple/README.md

@@ -9,7 +9,7 @@ for Dgraph.
 
 ### Start Dgraph server
 
-You will need to install [Dgraph v1.1.0 or above][releases] and run it.
+You will need to install [Dgraph v20.03.0 or above][releases] and run it.
 
 [releases]: https://github.com/dgraph-io/dgraph/releases
 

examples/simple/index.js

@@ -110,7 +110,7 @@ async function queryData(dgraphClient) {
         }
     }`;
     const vars = { $a: "Alice" };
-    const res = await dgraphClient.newTxn().queryWithVars(query, vars);
+    const res = await dgraphClient.newTxn({ readOnly: true }).queryWithVars(query, vars);
     const ppl = res.getJson();
 
     // Print results.

examples/simple/package.json

@@ -1,7 +1,7 @@
 {
   "name": "simple",
   "dependencies": {
-    "dgraph-js": "^2.1.0",
-    "grpc": "^1.23.3"
+    "dgraph-js": "^20.3.0",
+    "grpc": "^1.24.2"
   }
 }

examples/tls/README.md

@@ -10,7 +10,7 @@ cluster (1 Dgraph Zero and 1 Dgraph Alpha) configured with mutual TLS.
 
 ### Install Dgraph
 
-You will need to [install Dgraph v1.1.0 or
+You will need to [install Dgraph v20.03.0 or
 above](https://github.com/dgraph-io/dgraph/releases) and run it.
 
 A quick-start installation script is available for Linux and Mac:

examples/tls/index.js

@@ -122,7 +122,7 @@ async function queryData(dgraphClient) {
         }
     }`;
     const vars = { $a: "Alice" };
-    const res = await dgraphClient.newTxn().queryWithVars(query, vars);
+    const res = await dgraphClient.newTxn({ readOnly: true }).queryWithVars(query, vars);
     const ppl = res.getJson();
 
     // Print results.

examples/tls/package.json

@@ -1,7 +1,7 @@
 {
   "name": "tls",
   "dependencies": {
-    "dgraph-js": "^2.1.0",
-    "grpc": "^1.23.3"
+    "dgraph-js": "^20.3.0",
+    "grpc": "^1.24.2"
   }
 }