Apollo merge function

How does Apollo caching work?

With this policy, Apollo looks in the cache, and if all the data you requested is there, it's returned from the cache. Otherwise Apollo goes to the network, saves the new data in the cache, and returns that data to you.

What is Gql in Apollo?

But GraphQL is just a query language. And in order to use it easily, we need to use a platform that will do all the heavy lifting for us. One such platform is provided by Apollo. The Apollo platform is an implementation of GraphQL that can transfer data between the cloud (server) to the UI of your app .

What is the difference between readFragment and readQuery?

The readFragment method enables you to read data from any normalized cache object that was stored as part of any query result. Unlike readQuery , calls to readFragment do not need to conform to the structure of one of your data graph's supported queries.

What is key args in Apollo?

keyArgs function (advanced)

You can define a completely different format for a field's storage key by providing a custom function to keyArgs . This function takes the field's arguments and other context as parameters, and it can return any string to use as the storage key (or a dynamically-generated keyArgs array).

What is the best caching strategy?

A cache-aside cache is the most common caching strategy available. The fundamental data retrieval logic can be summarized as follows: When your application needs to read data from the database, it checks the cache first to determine whether the data is available.

What is '!' In GraphQL?

Define a field or a type, such as in a field: value pair used in an argument or when defining a variable. ! Indicates a non-nullable value type. By default, all value types in GraphQL can result in a null value. If a value type includes an exclamation point, it means that value cannot be null.

Is GraphQL overkill?

GraphQL can be overkill

Since GraphQL is so complex and powerful, it can commonly be overkill for smaller applications. If you have a simple/straight-forward app in front of you, it will be easier to work with a REST API.

What is difference between SQL and GQL?

SQL is a language that is built around tables whereas GQL is built around graphs. Users can use GQL to find and project a graph from a graph.

What is Root_query in Apollo?

The default value is ROOT_QUERY , which is the ID of the root query object. By specifying the ID of another cached object, you can query arbitrary cached data without conforming to the structure of your schema's supported queries. This enables readQuery to behave similarly to readFragment .

Why do we use args?

*args allows us to pass a variable number of non-keyword arguments to a Python function. In the function, we should use an asterisk ( * ) before the parameter name to pass a variable number of arguments.

What is ARG in coding?

Updated: 12/31/2022 by Computer Hope. Sometimes abbreviated as arg, referring to programming or the command line an argument is a value that is passed into a command, function, or routine.

What is L1 vs L2 vs L3 cache?

L2 cache is much larger than L1 but at the same time slower as well. They range from 4-8MB on flagship CPUs (512KB per core). Each core has its own L1 and L2 cache while the last level, the L3 cache is shared across all the cores on a die. L3 cache is the lowest-level cache.

Which is better L1 L2 or L3 cache?

L1 or L2 can be significantly faster than L3, though L3 is usually double the speed of DRAM. With multicore processors, each core can have dedicated L1 and L2 cache, but they can share an L3 cache. If an L3 cache references an instruction, it is usually elevated to a higher level of cache.

What is L1 L2 and L3 cache?

In its most basic terms, the data flows from the RAM to the L3 cache, then the L2, and finally, L1. When the processor is looking for data to carry out an operation, it first tries to find it in the L1 cache. If the CPU finds it, the condition is called a cache hit. It then proceeds to find it in L2 and then L3.

Does Apollo server cache?

Apollo Server uses an in-memory cache by default, but you can configure it to use a different backend, such as Redis or Memcached. You can specify a cache backend by passing a cache option to the ApolloServer constructor. Your specified cache backend must implement the KeyValueCache interface from the @apollo/utils.

How does database caching work?

A database cache supplements your primary database by removing unnecessary pressure on it, typically in the form of frequently accessed read data. The cache itself can live in a number of areas including your database, application or as a standalone layer.

Is Apollo cache persistent?

By default, the contents of your Apollo cache will be immediately restored (asynchronously, see how to persist data before rendering), and will be persisted upon every write to the cache (with a short debounce interval).

How does Apollo get their data?

Our data is accurate and up to date

We use third party vendors as well as our dialer data to verify direct dial and mobile numbers. Apollo's database is updated daily, with a guaranteed refund for every bounced email.

Is Apollo Client like Redux?

Apollo is suitable for managing remote data, and 20% of it was managed in a separate Redux Store, hence there is a need to integrate GraphQL and Redux. Apollo GraphQL no longer requires Redux. Apollo Client automatically catches the data and normalizes new data in query responses and after mutation.

Can I use Apollo Client with REST API?

You can use apollo-link-rest to call REST API inside your GraphQL queries.

Is Apollo a server or Client?

Apollo Server is an open-source, spec-compliant GraphQL server that's compatible with any GraphQL client, including Apollo Client. It's the best way to build a production-ready, self-documenting GraphQL API that can use data from any source.

Is cache faster than DB?

When query results are fetched, they are stored in the cache. The next time that information is needed, it is fetched from the cache instead of the database. This can reduce latency because data is fetched from memory, which is faster than disk.

Why is cache faster than DB?

A cache's primary purpose is to increase data retrieval performance by reducing the need to access the underlying slower storage layer. Trading off capacity for speed, a cache typically stores a subset of data transiently, in contrast to databases whose data is usually complete and durable.

What is L1 and L2 caching?

The first-level (L1) cache is small enough to provide a one- or two-cycle access time. The second-level (L2) cache is also built from SRAM but is larger, and therefore slower, than the L1 cache. The processor first looks for the data in the L1 cache. If the L1 cache misses, the processor looks in the L2 cache.