Primary index

Jump to the Code block for a combined complete example.

Basic PI queries have the following features:

Filter records by set name.
Filter records by Filter Expressions.
Limit the number of records returned, useful for pagination.
Return only record digests and metadata (generation and TTL).
Return specified bins.

Setup

The following examples will use the setup and record structure below to illustrate primary index queries in an Aerospike database.

const Aerospike = require('aerospike');
const exp = Aerospike.exp;

// Define host configuration
let config = {hosts: '127.0.0.1:3000'};

The record structure:

Occurred: Integer
Reported: Integer
Posted: Integer
Report: Map
{
    shape: List,
    summary: String,
    city: String,
    state: String,
    duration: String
}
Location: GeoJSON

Policies

See Basic Queries for query policy information.

Query a set

The following example queries the sandbox namespace and ufodata set name, while limiting the record set to only 20 records.

// Set max records to return
const maxRecords = 20;
let counter = 0;

// Create query
const query = client.query("sandbox", "ufodata");

// Execute the query
const recordStream = await query.foreach();

recordStream.on("error", (err) => {
  // Handle error
  console.log("query failed: " + err);
  recordStream.abort();
});

recordStream.on("data", (record) => {
  // Handle data
  counter++;
  console.info("Record: %o", record.bins);
  if (counter === maxRecords) {
    recordStream.abort();
  }
});

recordStream.on("end", async () => {
  // Close the connection to the server
  await client.close();
});

Query with a metadata filter

The following example queries the same namespace and set as the example above, but also adds a metadata Filter Expression that will only return records that are greater than 16 KiB.

// Create query policy
const queryPolicy = new Aerospike.QueryPolicy({
  filterExpression: exp.gt(exp.deviceSize(), exp.int(1024 * 16)),
});

// Create query
const query = client.query("sandbox", "ufodata");

// Execute the query
const recordStream = await query.foreach(queryPolicy);

recordStream.on("error", (err) => {
  // Handle error
  console.log("query failed: " + err);
  recordStream.abort();
});
recordStream.on("data", (record) => {
  // Handle data
  console.info("Record: %o", record.bins);
});
recordStream.on("end", async () => {
  // Close the connection to the server
  await client.close();
});

Query with a data filter

The following example queries the same namespace and set as the example above, but also adds a data Filter Expression that will only return records where the occurred bin value is in the inclusive range 20200101 to 20211231.

Take a look at secondary index queries to see how this same query can be run more efficiently with an index.

// Create query policy
const queryPolicy = new Aerospike.QueryPolicy({
  filterExpression: exp.let(
    exp.def("bin", exp.binInt("occurred")),
    exp.and(
      exp.ge(exp.var("bin"), exp.int(20220431)),
      exp.le(exp.var("bin"), exp.int(20220631)),
    ),
  ),
});

// Create query
const query = client.query("test", "demo");

// Execute the query
const recordStream = await query.foreach(queryPolicy);

recordStream.on("error", (err) => {
  console.log("query failed: " + err);
  recordStream.abort();
});
recordStream.on("data", (record) => {
  // handle record
  console.info("Record: %o\\n", record.bins);
});
recordStream.on("end", async () => {
  // Close the connection to the server
  await client.close();
});

Pagination

Pagination uses a combination of a partition filter and a defined maximum records to return query results. The partition filter maintains a cursor identifying the end of the current page and the beginning of the next. Moving to the next page of results is as simple as executing the query again, with the previously defined partition filter.

The following example executes a query with an Expression Filter identifying records with more than 3 shape items in the report map, returning 10 records per page. The partition filter is set to query all 4096 partitions in the database.

import { once } from "events";

// Create the expression
const filterExpression = exp.gt(
  exp.lists.size(
    exp.maps.getByKey(
      exp.binMap("report"),
      "shape",
      exp.type.LIST,
      maps.returnType.VALUE,
    ),
  ),
  exp.int(3),
);

// Create the policy
const queryPolicy = { filterExpression };

// Create the query
const query = client.query("test", "demo");

// Set max records
query.maxRecords = 10;

// Set paginate
query.paginate = true;

let stream = query.foreach();

stream.on("error", (error) => {
  throw error;
});

stream.on("data", (record) => {
  // handle data
  console.log(record.bins);
});

let queryState = await once(stream, "end");

query.nextPage(queryState[0]);

// Check to see if any pages are left
if (query.hasNextPage()) {
  stream = query.foreach();
} else {
  await client.close();
  process.exit(0);
}

stream.on("error", (error) => {
  throw error;
});

stream.on("data", (record) => {
  // handle data
  console.log(record.bins);
});

queryState = await once(stream, "end");

await client.close();

Code block

Expand this section for a single code block to execute a basic PI query

const Aerospike = await import("aerospike");
const exp = Aerospike.exp;

// Set hosts to your server's address and port
 const config = { hosts: "YOUR_HOST_ADDRESS:YOUR_PORT" };

// Establishes a connection to the server
const client = await Aerospike.connect(config);

// Create query
const query = client.query("test", "demo");

// Execute the query
const records = await query.results();

records.forEach((record) => {
  console.info("Record: %o", record.bins);
});

await client.close();