diff options
Diffstat (limited to 'src/include/utils/pg_lzcompress.h')
| -rw-r--r-- | src/include/utils/pg_lzcompress.h | 20 |
1 files changed, 11 insertions, 9 deletions
diff --git a/src/include/utils/pg_lzcompress.h b/src/include/utils/pg_lzcompress.h index bed75d9af17..fdd9701ee0e 100644 --- a/src/include/utils/pg_lzcompress.h +++ b/src/include/utils/pg_lzcompress.h @@ -3,7 +3,7 @@ * * Definitions for the builtin LZ compressor * - * $PostgreSQL: pgsql/src/include/utils/pg_lzcompress.h,v 1.14 2007/02/27 23:48:10 tgl Exp $ + * $PostgreSQL: pgsql/src/include/utils/pg_lzcompress.h,v 1.15 2007/08/04 21:53:00 tgl Exp $ * ---------- */ @@ -50,16 +50,18 @@ typedef struct PGLZ_Header * * min_input_size Minimum input data size to start compression. * - * force_input_size Input data size at which compressed storage is - * forced even if the compression rate drops below - * min_comp_rate (but not below 0). - * - * min_comp_rate Minimum compression rate (0-99%), the output - * must be smaller than the input. If that isn't + * force_input_size Minimum input data size to force compression + * even if the compression rate drops below + * min_comp_rate. But in any case the output + * must be smaller than the input. If that isn't * the case, the compressor will throw away its * output and copy the original, uncompressed data * to the output buffer. * + * min_comp_rate Minimum compression rate (0-99%) to require for + * inputs smaller than force_input_size. If not + * achieved, the output will be uncompressed. + * * match_size_good The initial GOOD match size when starting history * lookup. When looking up the history to find a * match that could be expressed as a tag, the @@ -70,8 +72,8 @@ typedef struct PGLZ_Header * longer the lookup takes, the smaller matches * are considered good. * - * match_size_drop The percentage, match_size_good is lowered - * at each history check. Allowed values are + * match_size_drop The percentage by which match_size_good is lowered + * after each history check. Allowed values are * 0 (no change until end) to 100 (only check * latest history entry at all). * ---------- |