Table properties : TableType

It has three dropdown 

• Regular
• InMemory
• TempDB

Regular:

The default value. These are permanent Tables. These tables are used for storing data permanently in the database.

InMemory:

• InMemory tables are never represented in the database management system. 
• The memory or disk space for the InMemory table is de-allocated as soon as the record buffer goes out of scope. 
• To free the memory and delete the file for the InMemory table, set the record buffer variable to null as follows.

                                custTmpLedger = null;

• The setTmp method is used to create an InMemory table from the Regular table.
• Indexes are useful for quickly retrieving data from InMemory tables, especially if the InMemory table data is in a disk file.
• The following code example copies data from the CustTable table into an InMemory table that is a copy of the CustTable table structure.

    static void CopyPersistedTableToInMemoryJob(Args _args)
    {
        CustTable custTable;
        CustTable custTmpLedger;
 
        custTmpLedger.setTmp();
        custTable.recordLevelSecurity(true);
 
        while select * from custTable where custTable.AccountNum like '1*'
        {
            custTmpLedger.data(custTable.data());
            custTmpLedger.doInsert();
            info(strFmt("Inserted a row for AccountNum = %1",custTable.AccountNum));
        }
 
        custTmpLedger = null;
    }

TempDB

InMemory tables	TempDB tables
1. Holds data temporarily in client or server tier	1. Holds data temporarily in the database until the scope is valid
2. These tables can't be stored in Database	2. These tables are stored in the database
3. Can't apply security	3. Can apply security
4. We cannot use InMemory table buffers	4. TempDB table buffer can be used in coding
5. SetTmp method to set the regular table to InMemory	5. linkPhysicalTableInstance method to set the regular table to TempDB

6. Can't apply joins

6. Can apply Joins