Analysis: Problem is that both encrypted tables and compressed tables use
FIL header offset FIL_PAGE_FILE_FLUSH_LSN_OR_KEY_VERSION to store
required metadata. Furhermore, for only compressed tables currently
code skips compression.
Fixes:
- Only encrypted pages store key_version to FIL header offset FIL_PAGE_FILE_FLUSH_LSN_OR_KEY_VERSION,
no need to fix
- Only compressed pages store compression algorithm to FIL header offset FIL_PAGE_FILE_FLUSH_LSN_OR_KEY_VERSION,
no need to fix as they have different page type FIL_PAGE_PAGE_COMPRESSED
- Compressed and encrypted pages now use a new page type FIL_PAGE_PAGE_COMPRESSED_ENCRYPTED and
key_version is stored on FIL header offset FIL_PAGE_FILE_FLUSH_LSN_OR_KEY_VERSION and compression
method is stored after FIL header similar way as compressed size, so that first
FIL_PAGE_COMPRESSED_SIZE is stored followed by FIL_PAGE_COMPRESSION_METHOD
- Fix buf_page_encrypt_before_write function to really compress pages if compression is enabled
- Fix buf_page_decrypt_after_read function to really decompress pages if compression is used
- Small style fixes
New generation hard drives, SSDs and NVM devices support 4K
sector size. Supported sector size can be found using fstatvfs()
or GetDiskFreeSpace() functions.
Analysis: InnoDB writes also files that do not contain FIL-header.
This could lead incorrect analysis on os_fil_read_func function
when it tries to see is page page compressed based on FIL_PAGE_TYPE
field on FIL-header. With bad luck uncompressed page that does
not contain FIL-headed, the byte on FIL_PAGE_TYPE position could
indicate that page is page comrpessed.
Fix: Upper layer must indicate is file space page compressed
or not. If this is not yet known, we need to read the FIL-header
and find it out. Files that we know that are not page compressed
we can always just provide FALSE.
SYNTAX: ATOMIC_WRITES=['DEFAULT','ON','OFF']
Idea here is to be able to define innodb_doublewrite = 1 but with following rules:
ATOMIC_WRITES='DEFAULT' - if innodb_use_atomic_writes = 1, we do not write to doublewrite buffer the changes
if innodb_use_atomic_writes = 0, we write to doublewrite buffer
ATOMIC_WRITES='ON' - do not write to doublewrite buffer
ATOMIC_WRITES='OFF' - write to doublewrite buffer
Note that doublewrite buffer can't be used if innodb_doublewrite = 0.
