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       COPY - copy data between a file and a table


       COPY tablename [ ( column [, ...] ) ]
           FROM { ’filename’ | STDIN }
           [ [ WITH ]
                 [ BINARY ]
                 [ OIDS ]
                 [ DELIMITER [ AS ] ’delimiter’ ]
                 [ NULL [ AS ] ’null string’ ]
                 [ CSV [ HEADER ]
                       [ QUOTE [ AS ] ’quote’ ]
                       [ ESCAPE [ AS ] ’escape’ ]
                       [ FORCE NOT NULL column [, ...] ]

       COPY { tablename [ ( column [, ...] ) ] | ( query ) }
           TO { ’filename’ | STDOUT }
           [ [ WITH ]
                 [ BINARY ]
                 [ OIDS ]
                 [ DELIMITER [ AS ] ’delimiter’ ]
                 [ NULL [ AS ] ’null string’ ]
                 [ CSV [ HEADER ]
                       [ QUOTE [ AS ] ’quote’ ]
                       [ ESCAPE [ AS ] ’escape’ ]
                       [ FORCE QUOTE column [, ...] ]


       COPY  moves  data  between  PostgreSQL  tables and standard file-system
       files. COPY TO copies the contents of a table to  a  file,  while  COPY
       FROM copies data from a file to a table (appending the data to whatever
       is in the table already). COPY TO can also copy the results of a SELECT

       If  a list of columns is specified, COPY will only copy the data in the
       specified columns to or from the file.  If there are any columns in the
       table  that  are  not  in  the  column  list, COPY FROM will insert the
       default values for those columns.

       COPY with a file name instructs the PostgreSQL server to directly  read
       from  or write to a file. The file must be accessible to the server and
       the name must be specified from the viewpoint of the server. When STDIN
       or  STDOUT is specified, data is transmitted via the connection between
       the client and the server.


              The name (optionally schema-qualified) of an existing table.

       column An optional list of columns to be copied. If no column  list  is
              specified, all columns of the table will be copied.

       query  A SELECT [select(7)] or VALUES [values(7)] command whose results
              are to be copied.  Note that parentheses are required around the

              The  absolute  path  name  of  the input or output file. Windows
              users might need to use an E’’  string  and  double  backslashes
              used as path separators.

       STDIN  Specifies that input comes from the client application.

       STDOUT Specifies that output goes to the client application.

       BINARY Causes  all  data  to  be stored or read in binary format rather
              than as text. You cannot specify the  DELIMITER,  NULL,  or  CSV
              options in binary mode.

       OIDS   Specifies  copying  the OID for each row. (An error is raised if
              OIDS is specified for a table that does not have OIDs, or in the
              case of copying a query.)

              The  single  ASCII  character that separates columns within each
              row (line) of the file. The default is a tab character  in  text
              mode, a comma in CSV mode.

       null string
              The  string  that  represents  a  null  value. The default is \N
              (backslash-N) in text mode, and an unquoted empty string in  CSV
              mode.  You  might  prefer  an empty string even in text mode for
              cases where you don’t  want  to  distinguish  nulls  from  empty

              Note:  When  using  COPY  FROM,  any data item that matches this
              string will be stored as a null value, so you should  make  sure
              that you use the same string as you used with COPY TO.

       CSV    Selects Comma Separated Value (CSV) mode.

       HEADER Specifies that the file contains a header line with the names of
              each column in the file. On output, the first line contains  the
              column  names  from  the  table, and on input, the first line is

       quote  Specifies the  ASCII  quotation  character  in  CSV  mode.   The
              default is double-quote.

       escape Specifies  the ASCII character that should appear before a QUOTE
              data character value in CSV mode.   The  default  is  the  QUOTE
              value (usually double-quote).

              In  CSV COPY TO mode, forces quoting to be used for all non-NULL
              values in each specified column.  NULL output is never quoted.

              In CSV COPY FROM mode, process each specified column  as  though
              it  were quoted and hence not a NULL value. For the default null
              string in CSV mode (’’), this causes missing values to be  input
              as zero-length strings.


       On  successful  completion, a COPY command returns a command tag of the

       COPY count

       The count is the number of rows copied.


       COPY can only be used with plain tables, not with views.  However,  you
       can write COPY (SELECT * FROM viewname) TO ....

       The  BINARY key word causes all data to be stored/read as binary format
       rather than as text. It is somewhat faster than the normal  text  mode,
       but  a binary-format file is less portable across machine architectures
       and PostgreSQL versions.  Also, the binary format  is  very  data  type
       specific;  for  example  it  will not work to output binary data from a
       smallint column and read it into an integer column,  even  though  that
       would work fine in text format.

       You  must  have  select privilege on the table whose values are read by
       COPY TO, and insert privilege  on  the  table  into  which  values  are
       inserted  by  COPY  FROM. It is sufficient to have column privileges on
       the column(s) listed in the command.

       Files named in a COPY command are  read  or  written  directly  by  the
       server,  not  by the client application. Therefore, they must reside on
       or be accessible to the database server machine, not the  client.  They
       must  be  accessible to and readable or writable by the PostgreSQL user
       (the user ID the server runs as), not the client. COPY naming a file is
       only allowed to database superusers, since it allows reading or writing
       any file that the server has privileges to access.

       Do not confuse COPY with the psql instruction \copy. \copy invokes COPY
       FROM  STDIN  or  COPY  TO STDOUT, and then fetches/stores the data in a
       file accessible to the psql client. Thus, file accessibility and access
       rights  depend on the client rather than the server when \copy is used.

       It is recommended that the file name used in COPY always  be  specified
       as an absolute path. This is enforced by the server in the case of COPY
       TO, but for COPY FROM you do have the option of  reading  from  a  file
       specified  by a relative path. The path will be interpreted relative to
       the working directory of the server  process  (normally  the  cluster’s
       data directory), not the client’s working directory.

       COPY  FROM  will  invoke  any  triggers  and  check  constraints on the
       destination table. However, it will not invoke rules.

       COPY input and output is affected by DateStyle. To  ensure  portability
       to  other PostgreSQL installations that might use non-default DateStyle
       settings, DateStyle should be set to ISO before using COPY  TO.  It  is
       also  a  good  idea  to  avoid  dumping  data with IntervalStyle set to
       sql_standard, because negative interval values might be  misinterpreted
       by a server that has a different setting for IntervalStyle.

       Input data is interpreted according to the current client encoding, and
       output data is encoded in the the current client encoding, even if  the
       data  does not pass through the client but is read from or written to a

       COPY stops operation at the  first  error.  This  should  not  lead  to
       problems  in  the event of a COPY TO, but the target table will already
       have received earlier rows in a COPY  FROM.  These  rows  will  not  be
       visible  or  accessible,  but  they still occupy disk space. This might
       amount to a considerable amount of wasted disk  space  if  the  failure
       happened  well  into  a  large copy operation. You might wish to invoke
       VACUUM to recover the wasted space.


       When COPY is used without the BINARY or CSV options, the data  read  or
       written  is  a text file with one line per table row.  Columns in a row
       are separated by the delimiter character.  The column values themselves
       are  strings  generated  by  the  output function, or acceptable to the
       input function, of each  attribute’s  data  type.  The  specified  null
       string is used in place of columns that are null.  COPY FROM will raise
       an error if any line of the input file contains more or  fewer  columns
       than are expected.  If OIDS is specified, the OID is read or written as
       the first column, preceding the user data columns.

       End of data can  be  represented  by  a  single  line  containing  just
       backslash-period  (\.).  An  end-of-data  marker  is not necessary when
       reading from a file, since the end of file serves perfectly well; it is
       needed  only  when  copying  data  to or from client applications using
       pre-3.0 client protocol.

       Backslash characters (\) can be used in the COPY  data  to  quote  data
       characters  that  might otherwise be taken as row or column delimiters.
       In particular, the following characters must be preceded by a backslash
       if  they  appear  as part of a column value: backslash itself, newline,
       carriage return, and the current delimiter character.

       The specified null string  is  sent  by  COPY  TO  without  adding  any
       backslashes;  conversely,  COPY FROM matches the input against the null
       string before removing backslashes. Therefore, a null string such as \N
       cannot  be  confused  with  the  actual  data  value \N (which would be
       represented as \\N).

       The following special backslash sequences are recognized by COPY  FROM:
       SequenceRepresents\bBackspace  (ASCII 8)\fForm feed (ASCII 12)\nNewline
       (ASCII 10)\rCarriage return (ASCII  13)\tTab  (ASCII  9)\vVertical  tab
       (ASCII  11)\digitsBackslash  followed  by  one  to  three  octal digits
       specifies the  character  with  that  numeric  code\xdigitsBackslash  x
       followed  by  one  or  two hex digits specifies the character with that
       numeric code Presently, COPY TO will never emit an octal or  hex-digits
       backslash  sequence,  but  it does use the other sequences listed above
       for those control characters.

       Any other backslashed character that is  not  mentioned  in  the  above
       table  will  be  taken  to  represent itself. However, beware of adding
       backslashes unnecessarily, since  that  might  accidentally  produce  a
       string  matching  the end-of-data marker (\.) or the null string (\N by
       default). These strings will be recognized before any  other  backslash
       processing is done.

       It  is  strongly  recommended  that  applications  generating COPY data
       convert data newlines and carriage returns to the \n and  \r  sequences
       respectively.  At  present  it is possible to represent a data carriage
       return by a backslash and carriage return,  and  to  represent  a  data
       newline  by  a  backslash  and newline.  However, these representations
       might not be  accepted  in  future  releases.   They  are  also  highly
       vulnerable  to  corruption  if  the  COPY  file  is  transferred across
       different machines (for example, from Unix to Windows or vice versa).

       COPY TO will terminate each row with  a  Unix-style  newline  (‘‘\n’’).
       Servers   running   on   Microsoft   Windows  instead  output  carriage
       return/newline (‘‘\r\n’’), but only for COPY  to  a  server  file;  for
       consistency  across  platforms,  COPY  TO  STDOUT  always  sends ‘‘\n’’
       regardless of server platform.  COPY FROM can handle lines ending  with
       newlines,  carriage returns, or carriage return/newlines. To reduce the
       risk of error due to un-backslashed newlines or carriage  returns  that
       were  meant as data, COPY FROM will complain if the line endings in the
       input are not all alike.

       This format is used for importing and  exporting  the  Comma  Separated
       Value   (CSV)  file  format  used  by  many  other  programs,  such  as
       spreadsheets. Instead of the escaping  used  by  PostgreSQL’s  standard
       text   mode,  it  produces  and  recognizes  the  common  CSV  escaping

       The values in each record are separated by the DELIMITER character.  If
       the  value  contains  the delimiter character, the QUOTE character, the
       NULL string, a carriage return, or line feed character, then the  whole
       value  is  prefixed  and  suffixed  by  the  QUOTE  character,  and any
       occurrence within  the  value  of  a  QUOTE  character  or  the  ESCAPE
       character  is preceded by the escape character.  You can also use FORCE
       QUOTE to force quotes  when  outputting  non-NULL  values  in  specific

       The  CSV format has no standard way to distinguish a NULL value from an
       empty string.  PostgreSQL’s COPY handles this by quoting.   A  NULL  is
       output as the NULL parameter string and is not quoted, while a non-NULL
       value matching the NULL parameter string is quoted. For  example,  with
       the  default  settings,  a NULL is written as an unquoted empty string,
       while an empty string data value is written with  double  quotes  ("").
       Reading  values  follows  similar  rules. You can use FORCE NOT NULL to
       prevent NULL input comparisons for specific columns.

       Because backslash is not a special character in the CSV format, \., the
       end-of-data  marker,  could  also  appear as a data value. To avoid any
       misinterpretation, a \.  data value appearing as a lone entry on a line
       is  automatically  quoted  on  output,  and on input, if quoted, is not
       interpreted as the end-of-data  marker.  If  you  are  loading  a  file
       created  by  another  application that has a single unquoted column and
       might have a value of \., you might need to quote  that  value  in  the
       input file.

              Note:  In  CSV  mode,  all  characters are significant. A quoted
              value surrounded by white space, or any  characters  other  than
              DELIMITER,  will include those characters. This can cause errors
              if you import data from a system that pads CSV lines with  white
              space  out  to  some fixed width. If such a situation arises you
              might need to preprocess the CSV file  to  remove  the  trailing
              white space, before importing the data into PostgreSQL.

              Note:  CSV  mode  will both recognize and produce CSV files with
              quoted values containing  embedded  carriage  returns  and  line
              feeds.  Thus  the  files are not strictly one line per table row
              like text-mode files.

              Note: Many programs produce strange  and  occasionally  perverse
              CSV  files,  so  the  file  format  is  more a convention than a
              standard. Thus you might encounter some  files  that  cannot  be
              imported using this mechanism, and COPY might produce files that
              other programs cannot process.

       The file format used for COPY BINARY changed in PostgreSQL 7.4. The new
       format  consists  of  a file header, zero or more tuples containing the
       row data, and a file trailer. Headers and data are now in network  byte

       The  file  header  consists  of 15 bytes of fixed fields, followed by a
       variable-length header extension area. The fixed fields are:

              11-byte sequence PGCOPY\n\377\r\n\0 — note that the zero byte is
              a  required part of the signature. (The signature is designed to
              allow easy identification of files that have been  munged  by  a
              non-8-bit-clean transfer. This signature will be changed by end-
              of-line-translation filters, dropped zero  bytes,  dropped  high
              bits, or parity changes.)

       Flags field
              32-bit  integer bit mask to denote important aspects of the file
              format. Bits are numbered from 0 (LSB) to 31  (MSB).  Note  that
              this  field  is  stored  in network byte order (most significant
              byte first), as are all the integer  fields  used  in  the  file
              format.  Bits  16-31 are reserved to denote critical file format
              issues; a reader should abort if it finds an unexpected bit  set
              in  this  range.  Bits  0-15  are  reserved to signal backwards-
              compatible format issues; a  reader  should  simply  ignore  any
              unexpected  bits  set in this range. Currently only one flag bit
              is defined, and the rest must be zero:

              Bit 16 if 1, OIDs are included in the data; if 0, not

       Header extension area length
              32-bit integer, length in bytes  of  remainder  of  header,  not
              including  self.   Currently,  this is zero, and the first tuple
              follows immediately. Future changes to the  format  might  allow
              additional  data  to  be  present in the header. A reader should
              silently skip over any header extension data it  does  not  know
              what to do with.

       The  header extension area is envisioned to contain a sequence of self-
       identifying chunks. The flags field is not  intended  to  tell  readers
       what  is  in  the  extension  area. Specific design of header extension
       contents is left for a later release.

       This design allows for both backwards-compatible header additions  (add
       header extension chunks, or set low-order flag bits) and non-backwards-
       compatible changes (set high-order flag bits to  signal  such  changes,
       and add supporting data to the extension area if needed).

       Each  tuple  begins with a 16-bit integer count of the number of fields
       in the tuple. (Presently, all tuples in a  table  will  have  the  same
       count,  but  that  might  not  always be true.) Then, repeated for each
       field in the tuple, there is a 32-bit length word followed by that many
       bytes  of field data. (The length word does not include itself, and can
       be zero.) As a special case, -1 indicates a NULL field value. No  value
       bytes follow in the NULL case.

       There is no alignment padding or any other extra data between fields.

       Presently,  all  data values in a COPY BINARY file are assumed to be in
       binary format (format code  one).  It  is  anticipated  that  a  future
       extension  might add a header field that allows per-column format codes
       to be specified.

       To determine the appropriate binary format for the  actual  tuple  data
       you  should  consult the PostgreSQL source, in particular the *send and
       *recv functions for each column’s data type (typically these  functions
       are  found  in  the  src/backend/utils/adt/  directory  of  the  source

       If OIDs are included in the file, the OID field immediately follows the
       field-count word. It is a normal field except that it’s not included in
       the field-count. In particular it has a length word — this  will  allow
       handling  of  4-byte  vs.  8-byte  OIDs without too much pain, and will
       allow OIDs to be shown as null if that ever proves desirable.

       The file trailer consists of a 16-bit integer word containing -1.  This
       is easily distinguished from a tuple’s field-count word.

       A reader should report an error if a field-count word is neither -1 nor
       the expected number of columns. This provides an  extra  check  against
       somehow getting out of sync with the data.


       The  following  example copies a table to the client using the vertical
       bar (|) as the field delimiter:


       To copy data from a file into the country table:

       COPY country FROM ’/usr1/proj/bray/sql/country_data’;

       To copy into a file just the countries whose names start with ’A’:

       COPY (SELECT * FROM country WHERE country_name LIKE ’A%’) TO ’/usr1/proj/bray/sql/a_list_countries.copy’;

       Here is a sample of data suitable for copying into a table from STDIN:

       AF      AFGHANISTAN
       AL      ALBANIA
       DZ      ALGERIA
       ZM      ZAMBIA
       ZW      ZIMBABWE

       Note that the white space on each line is actually a tab character.

       The following is the same data, output in binary format.  The  data  is
       shown  after  filtering  through  the Unix utility od -c. The table has
       three columns; the first has type char(2), the second  has  type  text,
       and  the  third has type integer. All the rows have a null value in the
       third column.

       0000000   P   G   C   O   P   Y  \n 377  \r  \n  \0  \0  \0  \0  \0  \0
       0000020  \0  \0  \0  \0 003  \0  \0  \0 002   A   F  \0  \0  \0 013   A
       0000040   F   G   H   A   N   I   S   T   A   N 377 377 377 377  \0 003
       0000060  \0  \0  \0 002   A   L  \0  \0  \0 007   A   L   B   A   N   I
       0000100   A 377 377 377 377  \0 003  \0  \0  \0 002   D   Z  \0  \0  \0
       0000120 007   A   L   G   E   R   I   A 377 377 377 377  \0 003  \0  \0
       0000140  \0 002   Z   M  \0  \0  \0 006   Z   A   M   B   I   A 377 377
       0000160 377 377  \0 003  \0  \0  \0 002   Z   W  \0  \0  \0  \b   Z   I
       0000200   M   B   A   B   W   E 377 377 377 377 377 377


       There is no COPY statement in the SQL standard.

       The following syntax was used before  PostgreSQL  version  7.3  and  is
       still supported:

       COPY [ BINARY ] tablename [ WITH OIDS ]
           FROM { ’filename’ | STDIN }
           [ [USING] DELIMITERS ’delimiter’ ]
           [ WITH NULL AS ’null string’ ]

       COPY [ BINARY ] tablename [ WITH OIDS ]
           TO { ’filename’ | STDOUT }
           [ [USING] DELIMITERS ’delimiter’ ]
           [ WITH NULL AS ’null string’ ]