Composite Storage support CTAS

[tabshi]

I have a table stored in Sled. Due to the large amount of data, the join query speed is very slow. I want to copy this table into memory, using Composite Storage for querying. I attempted to create it using the following SQL statement:

           let memory_storage = MemoryStorage::default();
           let mut storage = CompositeStorage::new();
           let Glue {
               storage: sled_storage,
           } = &*db.lock();
           storage.push("MEM", memory_storage);
           storage.push("SLED", sled_storage.clone());
           storage.set_default("SLED");
           let mut glue = Glue::new(storage);
           let start_time = Instant::now();
           let res = &glue
               .execute("CREATE TABLE MEM_material ENGINE = MEM AS (SELECT * FROM material);")
               .unwrap();

CREATE TABLE MEM_material ENGINE = MEM AS (SELECT * FROM material);

However, a syntax error occurred. Is there a problem with my usage, or does Composite Storage not currently support this syntax?

[suncunxudsb]

Yes, I also encountered this problem. Have you solved it

[tabshi]

noup

[wawnchg]

I have the same problem, is there any good solution?

[henry]

Currently, CTAS does not work with ENGINE option but only works with default storage.
So, you could do like this.

storage.push("MEM", memory_storage);
storage.push("SLED", sled_storage.clone());
storage.set_default("MEMORY");
let mut glue = Glue::new(storage);

glue.execute("CREATE TABLE material (id INT, name TEXT) ENGINE = SLED;");
// insert data
glue.execute("CREATE TABLE MEM_material AS SELECT * FROM material;");

By the way, Can you guys { @enginefuture, @suncunxudsb, @wawnchg } share below information? It might help a lot to improve query performance.

• The slow query
• The row number of each tables in the slow query
• Schema of each tables
• PK on each tables
• Indexes on each tables