1DB_LOAD(1) BerkeleyDB Utilities DB_LOAD(1)
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6 db_load - Read and load data from standard input
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9 db_load [-nTV] [-b blob-dir] [-c name=value] [-f input] [-h home] [-P
10 password] [-o blob-threshold] [-t btree | hash | queue | recno] file
11 db_load [-r lsn | fileid] [-h home] [-P password] file
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15 The db_load utility reads from the standard input and loads it into the
16 database file. The database file is created if it does not already
17 exist.
18 The input to db_load must be in the output format specified by the
20 db_dump utility, or as specified for the -T below.
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23 -b blob-dir
24 Identifies the directory where BLOB data is stored. If this
25 option is not specified, then BLOB data is placed in a subdirec‐
26 tory within the DB's environment. See also the -o option.
27 -c name=value
29 Specify configuration options ignoring any value they may have
30 based on the input. The command-line format is name=value. See
31 the Supported Keywords section below for a list of keywords sup‐
32 ported by the -c option.
33 -f input
35 Read from the specified input file instead of from the standard
36 input.
37 -h home
39 Specify a home directory for the database environment.
40 If a home directory is specified, the database environment is
42 opened using the DB_INIT_LOCK, DB_INIT_LOG, DB_INIT_MPOOL,
43 DB_INIT_TXN, and DB_USE_ENVIRON flags to DB_ENV->open. (This
44 means that db_load can be used to load data into databases while
45 they are in use by other processes.) If the DB_ENV->open call
46 fails, or if no home directory is specified, the database is
47 still updated, but the environment is ignored; for example, no
48 locking is done.
49 -n Do not overwrite existing keys in the database when loading into
51 an already existing database. If a key/data pair cannot be
52 loaded into the database for this reason, a warning message is
53 displayed on the standard error output, and the key/data pair
54 are skipped.
55 -o blob-threshold
57 Identifies the BLOB threshold in bytes. This threshold deter‐
58 mines when a data item will be stored as a BLOB. Data items
59 sized less than this threshold are stored as normal data within
60 the database. Data items larger than this size are stored on-
61 disk in a subdirectory set aside for the purpose. Use the -b
62 command line option to identify where BLOB data is stored.
63 -P password
65 Specify an environment password. Although Berkeley DB utilities
66 overwrite password strings as soon as possible, be aware there
67 may be a window of vulnerability on systems where unprivileged
68 users can see command-line arguments or where utilities are not
69 able to overwrite the memory containing the command-line argu‐
70 ments.
71 -r Reset the database's file ID or log sequence numbers (LSNs).
73 All database pages in transactional environments contain refer‐
75 ences to the environment's log records. In order to copy a
76 database into a different database environment, database page
77 references to the old environment's log records must be reset,
78 otherwise data corruption can occur when the database is modi‐
79 fied in the new environment. The -r lsn option resets a data‐
80 base's log sequence numbers.
81 All databases contain an ID string used to identify the database
83 in the database environment cache. If a database is copied, and
84 used in the same environment as another file with the same ID
85 string, corruption can occur. The -r fileid option resets a
86 database's file ID to a new value.
87 In both cases, the physical file specified by the file argument
89 is modified in-place.
90 -T The -T option allows non-Berkeley DB applications to easily load
92 text files into databases.
93 If the database to be created is of type Btree or Hash, or the
95 keyword keys is specified as set, the input must be paired lines
96 of text, where the first line of the pair is the key item, and
97 the second line of the pair is its corresponding data item. If
98 the database to be created is of type Queue or Recno and the
99 keyword keys is not set, the input must be lines of text, where
100 each line is a new data item for the database.
101 A simple escape mechanism, where newline and backslash (\) char‐
103 acters are special, is applied to the text input. Newline char‐
104 acters are interpreted as record separators. Backslash charac‐
105 ters in the text will be interpreted in one of two ways: If the
106 backslash character precedes another backslash character, the
107 pair will be interpreted as a literal backslash. If the back‐
108 slash character precedes any other character, the two characters
109 following the backslash will be interpreted as a hexadecimal
110 specification of a single character; for example, \0a is a new‐
111 line character in the ASCII character set.
112 For this reason, any backslash or newline characters that natu‐
114 rally occur in the text input must be escaped to avoid misinter‐
115 pretation by db_load.
116 If the -T option is specified, the underlying access method type
118 must be specified using the -t option.
119 -t Specify the underlying access method. If no -t option is speci‐
121 fied, the database will be loaded into a database of the same
122 type as was dumped; for example, a Hash database will be created
123 if a Hash database was dumped.
124 Btree and Hash databases may be converted from one to the other.
126 Queue and Recno databases may be converted from one to the
127 other. If the -k option was specified on the call to db_dump
128 then Queue and Recno databases may be converted to Btree or
129 Hash, with the key being the integer record number.
130 -V Write the library version number to the standard output, and
132 exit.
133 The db_load utility may be used with a Berkeley DB environment (as
135 described for the -h option, the environment variable DB_HOME, or
136 because the utility was run in a directory containing a Berkeley DB
137 environment). In order to avoid environment corruption when using a
138 Berkeley DB environment, db_load should always be given the chance to
139 detach from the environment and exit gracefully. To cause db_load to
140 release all environment resources and exit cleanly, send it an inter‐
141 rupt signal (SIGINT).
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144 The db_load utility exits 0 on success, 1 if one or more key/data pairs
145 were not loaded into the database because the key already existed, and
146 >1 if an error occurs.
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149 DB_HOME
150 If the -h option is not specified and the environment variable
151 DB_HOME is set, it is used as the path of the database home, as
152 described in DB_ENV->open.
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155 The db_load utility can be used to load text files into databases. For
156 example, the following command loads the standard UNIX /etc/passwd file
157 into a database, with the login name as the key item and the entire
158 password entry as the data item:
159 awk -F: '{print $1; print $0}' < /etc/passwd |
161 sed 's/\\/\\\\/g' | db_load -T -t hash passwd.db
162 Note that backslash characters naturally occurring in the text are
164 escaped to avoid interpretation as escape characters by db_load.
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167 The following keywords are supported for the -c command-line ption to
168 the db_load utility. See DB->open for further discussion of these key‐
169 words and what values should be specified.
170 The parenthetical listing specifies how the value part of the
172 name=value pair is interpreted. Items listed as (boolean) expect value
173 to be 1 (set) or 0 (unset). Items listed as (number) convert value to
174 a number. Items listed as (string) use the string value without modi‐
175 fication.
176 bt_minkey (number)
178 The minimum number of keys per page.
179 chksum (boolean)
181 Enable page checksums.
182 database (string)
184 The database to load.
185 db_lorder (number)
187 The byte order for integers in the stored database metadata.
188 db_pagesize (number)
190 The size of database pages, in bytes.
191 duplicates (boolean)
193 The value of the DB_DUP flag.
194 dupsort (boolean)
196 The value of the DB_DUPSORT flag.
197 extentsize (number)
199 The size of database extents, in pages, for Queue databases con‐
200 figured to use extents.
201 h_ffactor (number)
203 The density within the Hash database.
204 h_nelem (number)
206 The size of the Hash database.
207 keys (boolean)
209 Specify whether keys are present for Queue or Recno databases.
210 re_len (number)
212 Specify fixed-length records of the specified length.
213 re_pad (string)
215 Specify the fixed-length record pad character.
216 recnum (boolean)
218 The value of the DB_RECNUM flag.
219 renumber (boolean)
221 The value of the DB_RENUMBER flag.
222 subdatabase (string)
224 The subdatabase to load.
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227 db_archive(1) db_checkpoint(1) db_deadlock(1) db_dump(1) db_hot‐
228 backup(1) db_log_verify(1) db_printlog(1) db_recover(1) db_replicate(1)
229 db_stat(1) db_tuner(1) db_upgrade(1) db_verify(1)
230BerkeleyDB 5.3.28 06 December 2016 DB_LOAD(1)