Integrating tablespaces with different block sizes

Abstract

Provided herein is a mechanism that allows a given database system to access data blocks from another database system, where data blocks from the given database system and data blocks from the other database system have different sizes. According to an aspect of the present invention, a tablespace in the other database system contained the data blocks. The tablespace is detached from the other database system and integrated into the given database, which is capable of processing data stored in data blocks of different sizes.

1 . A method for database systems to access data from other database systems, the method comprising the steps of: 
 a first database system storing in a buffer cache first data blocks having a first data block size, wherein said first database system includes said buffer cache and stores data blocks of multiple sizes within said buffer cache;    concurrently with said first database system storing in said buffer cache first data blocks having a first data block size, said first database system storing in said buffer cache a copy of second data blocks in which a second database system stored second database records;    said second data blocks having at least one data block with a second data block size different than said first data block size; and    wherein each block of said first data blocks and of said second data blocks is an atomic unit of storage space allocated within a file to store one or more records of a database.    
   
   
       2 . The method of  claim 1 , wherein said buffer cache comprises first buffers for storing buffers of said first data block size and second buffers for storing buffers of said second data block size, and wherein said first buffers are of a different size than said second buffers.  
   
   
       3 . The method of  claim 1 , wherein the step of accessing a copy of second data blocks includes storing user data in said copy of said second data blocks.  
   
   
       4 . The method of  claim 1 , wherein the method further includes the step of detaching one or more tablespaces from said second database system, wherein said one or more tablespaces include said second data blocks.  
   
   
       5 . The method of  claim 1 , further including the step of the first database system generating metadata that specifies a plurality of block sizes for data blocks directly accessible to said first database system.  
   
   
       6 . The method of  claim 5 , wherein: 
 the first database system generating metadata that specifies a plurality of block sizes for data blocks directly accessible to said first database system;    wherein said metadata defines tablespaces and specifies for each tablespace of said tablespaces a particular data block size for data blocks in said tablespace; and    wherein the method further comprises the step of integrating said copy of said second data blocks within said first database system as at least one tablespace that includes said copy of said second data blocks, wherein the step of integrating includes modifying said metadata to reflect said second data block size for said at least one tablespace.    
   
   
       7 . The method of  claim 1 , wherein said first database system is a data warehouse and said second database system is a source database system for said data warehouse.  
   
   
       8 . The method of  claim 7 , further including the step of integrating said copy of said second data blocks within said data warehouse as a tablespace that includes said copy of said second data blocks.  
   
   
       9 . A method for database systems to access data from other database systems, the method comprising the steps of: 
 a first database system directly storing first database records in first data blocks having a first data block size;    concurrently with said first database system directly storing first database records in first data blocks having a first data block size, said first database system directly accessing a copy of second data blocks in which a second database system directly stored second database records;    said second data blocks having at least one data block with a second data block size different than said first data block size; and    wherein each block of said first data blocks and of said second data blocks is an atomic unit of storage space allocated within a file to store one or more records of a database.    
   
   
       10 . The method of  claim 9 , wherein the method further includes the step of integrating said copy of said second data blocks within said first database system as a tablespace that includes said copy of said second data blocks.  
   
   
       11 . The method of  claim 9 , wherein the step of accessing a copy of second data blocks includes storing user data in said copy of said second data blocks.  
   
   
       12 . The method of  claim 9 , wherein the method further includes the step of detaching one or more tablespaces from said second database system, wherein said one or more tablespaces include said second data blocks.  
   
   
       13 . The method of  claim 9 , wherein each data block of said copy of said second data blocks has said second data block size.  
   
   
       14 . The method of  claim 9 , further including the step of the first database system generating metadata that specifies a plurality of block sizes for data blocks directly accessible to said first database system.  
   
   
       15 . The method of  claim 14 , wherein: 
 said metadata defines tablespaces and specifies for each tablespace of said tablespaces a particular data block size for all data blocks in said tablespace; and    the method further includes the step of integrating said copy of said second data blocks within said first database system as at least one tablespace that includes said copy of said second data blocks, and    wherein the step of integrating includes modifying said metadata to reflect said second data block size for said at least one tablespace.    
   
   
       16 . The method of  claim 9 , wherein said first database system is a data warehouse and said second database system is a source database system for said data warehouse.  
   
   
       17 . The method of  claim 16 , further including the step of integrating said copy of said second data blocks within said data warehouse as a tablespace that includes said copy of said second data blocks.  
   
   
       18 . The method of  claim 9 , 
 wherein first data files contain said first data blocks and second data files contain said second data blocks; and    wherein the method further includes the step of generating a mapping: 
 between said first data files and said first data block size, and  
 between said second data files and said second data block size.  
   
   
   
       19 . The method of  claim 9 , 
 wherein a first tablespace contains said first data blocks and a second tablespace contains said second data blocks; and    wherein the method further includes the step of generating a mapping: 
 between said first tablespace and said first data block size, and  
 between said second tablespace and said second data block size.  
   
   
   
       20 . The method of  claim 9 , wherein: 
 a first tablespace includes said first data blocks;    a second tablespace includes said second data blocks; and 
 the method further includes the step of generating metadata that defines the first data block size as a size of data blocks in said first tablespace and defines the second block size as a size of data blocks in said second tablespace.  
   
   
   
       21 . The method of  claim 9 , 
 wherein said first database system includes a buffer cache in which said first database system stores data blocks of multiple sizes; and    wherein said method further includes the step of concurrently storing said first data blocks and said second data blocks in said buffer cache.    
   
   
       22 . A computer-readable medium carrying one or more sequences of instructions for database systems to access data from other database systems, wherein execution of the one or more sequences of instructions by one or more processors causes the one or more processors to perform the steps of: 
 a first database system directly storing first database records in first data blocks having a first data block size, wherein said first database system includes a buffer cache in which said first database system stores data blocks of multiple sizes;    concurrently with said first database system directly storing first database records in first data blocks having a first data block size, said first database system directly accessing a copy of second data blocks in which a second database system directly stored second database records;    said second data blocks having at least one data block with a second data block size different than said first data block size;    concurrently storing said first data blocks and said second data blocks in said buffer cache, wherein each block of said first data blocks and of said second data blocks is an atomic unit of storage space allocated within a file to store one or more records of a database.    
   
   
       23 . The computer-readable medium of  claim 22 , wherein said buffer cache comprises first buffers for storing buffers of said first data block size and second buffers for storing buffers of said second data block size, and wherein said first buffers are of a different size than said second buffers.  
   
   
       24 . The computer-readable medium of  claim 22 , wherein the step of accessing a copy of second data blocks includes storing user data in said copy of said second data blocks.  
   
   
       25 . The computer-readable medium of  claim 22 , wherein the method further includes the step of detaching one or more tablespaces from said second database system, wherein said one or more tablespaces include said second data blocks.  
   
   
       26 . The computer-readable medium of  claim 22 , further including the step of the first database system generating metadata that specifies a plurality of block sizes for data blocks directly accessible to said first database system.  
   
   
       27 . The computer-readable medium of  claim 26 , wherein: 
 the first database system generating metadata that specifies a plurality of block sizes for data blocks directly accessible to said first database system;    wherein said metadata defines tablespaces and specifies for each tablespace of said tablespaces a particular data block size for data blocks in said tablespace; and    the computer-readable medium further carrying instructions for integrating said copy of said second data blocks within said first database system as at least one tablespace that includes said copy of said second data blocks, wherein the step of integrating includes modifying said metadata to reflect said second data block size for said at least one tablespace.    
   
   
       28 . The computer-readable medium of  claim 22 , wherein said first database system is a data warehouse and said second database system is a source database system for said data warehouse.  
   
   
       29 . The computer-readable medium of  claim 28 , further including the step of integrating said copy of said second data blocks within said data warehouse as a tablespace that includes said copy of said second data blocks.  
   
   
       30 . A computer-readable medium carrying one or more sequences of instructions for database systems to access data from other database systems, wherein execution of the one or more sequences of instructions by one or more processors causes the one or more processors to perform the steps of: 
 a first database system directly storing first database records in first data blocks having a first data block size;    concurrently with said first database system directly storing first database records in first data blocks having a first data block size, said first database system directly accessing a copy of second data blocks in which a second database system directly stored second database records;    said second data blocks having at least one data block with a second data block size different than said first data block size; and    wherein each block of said first data blocks and of said second data blocks is an atomic unit of storage space allocated within a file to store one or more records of a database.    
   
   
       31 . The computer-readable medium of  claim 30 , wherein the computer-readable medium further includes instructions for performing the step of integrating said copy of said second data blocks within said first database system as a tablespace that includes said copy of said second data blocks.  
   
   
       32 . The computer-readable medium of  claim 30 , wherein the step of accessing a copy of second data blocks includes storing user data in said copy of said second data blocks.  
   
   
       33 . The computer-readable medium of  claim 30 , wherein the computer-readable medium further includes instructions for performing the step of detaching one or more tablespaces from said second database system, wherein said one or more tablespaces include said second data blocks.  
   
   
       34 . The computer-readable medium of  claim 30 , wherein each data block of said copy of said second data blocks has said second data block size.  
   
   
       35 . The computer-readable medium of  claim 30 , further including instructions for performing the step of the first database system generating metadata that specifies a plurality of block sizes for data blocks directly accessible to said first database system.  
   
   
       36 . The computer-readable medium of  claim 35 , wherein: 
 said metadata defines tablespaces and specifies for each tablespace of said tablespaces a particular data block size for all data blocks in said tablespace; and    the computer-readable medium further includes instructions for performing the step of integrating said copy of said second data blocks within said first database system as at least one tablespace that includes said copy of said second data blocks, and    wherein the step of integrating includes modifying said metadata to reflect said second data block size for said at least one tablespace.    
   
   
       37 . The computer-readable medium of  claim 30 , wherein said first database system is a data warehouse and said second database system is a source database system for said data warehouse.  
   
   
       38 . The computer-readable medium of  claim 37 , further including instructions for performing the step of integrating said copy of said second data blocks within said data warehouse as a tablespace that includes said copy of said second data blocks.  
   
   
       39 . The computer-readable medium of  claim 30 , 
 wherein first data files contain said first data blocks and second data files contain said second data blocks; and    wherein the computer-readable medium further includes instructions for performing the step of generating a mapping: 
 between said first data files and said first data block size, and  
 between said second data files and said second data block size.  
   
   
   
       40 . The computer-readable medium of  claim 30 , 
 wherein a first tablespace contains said first data blocks and a second tablespace contains said second data blocks; and    wherein the computer-readable medium further includes instructions for performing the step of generating a mapping: 
 between said first tablespace and said first data block size, and  
 between said second tablespace and said second data block size.  
   
   
   
       41 . The computer-readable medium of  claim 30 , 
 wherein said first database system includes a buffer cache in which said first database system stores data blocks of multiple sizes; and    wherein said computer-readable medium further includes the step of concurrently storing said first data blocks and said second data blocks in said buffer cache.    
   
   
       42 . The computer-readable medium of  claim 30 , wherein: 
 a first tablespace includes said first data blocks;    a second tablespace includes said second data blocks; and    the computer-readable medium further includes instructions for generating metadata that defines the first data block size as a size of data blocks in said first tablespace and defines the second block size as a size of data blocks in said second tablespace.