SPLASH allows you to store data inside data structures for later use. There are three main types: vectors, dictionaries, and event caches.
While dictionary and vector data structures can be defined globally, global use should be limited to reading them. Only one stream should write to a dictionary or vector data structure. And while that stream is writing, no other stream should write to or read from that data structure. The underlying objects used to manage the global dictionary or vector data structures are not thread-safe. A stream must have exclusive access to the global dictionary or vector data structure while writing. Allowing other streams to access these data structures while one stream is writing can result in server failure.
Use of these data structures should be limited to relatively static data (such as country codes) that will not need to be updated during processing, but will be read by multiple streams. Writing the data to the dictionary or vector must be completed before any streams read it.
All operations that read a global dictionary or vector should perform an isnull check, as shown in this example:
typeof(streamname) rec := dict[symbol];
if( not (isnull(rec)) {
// use rec
}