COPY — copy data between a file and a table
COPYtable_name[ (column_name[, ...] ) ] FROM { 'filename' | PROGRAM 'command' | STDIN } [ [ WITH ] (option[, ...] ) ] [ WHEREcondition] COPY {table_name[ (column_name[, ...] ) ] | (query) } TO { 'filename' | PROGRAM 'command' | STDOUT } [ [ WITH ] (option[, ...] ) ] whereoptioncan be one of: FORMATformat_nameFREEZE [boolean] DELIMITER 'delimiter_character' NULL 'null_string' HEADER [boolean] QUOTE 'quote_character' ESCAPE 'escape_character' FORCE_QUOTE { (column_name[, ...] ) | * } FORCE_NOT_NULL (column_name[, ...] ) FORCE_NULL (column_name[, ...] ) ENCODING 'encoding_name'
   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 query.
  
   If a column list is specified, COPY TO copies only
   the data in the specified columns to the file.  For COPY
   FROM, each field in the file is inserted, in order, into the
   specified column.  Table columns not specified in the COPY
   FROM column list will receive their default values.
  
   COPY with a file name instructs the
   PostgreSQL server to directly read from
   or write to a file. The file must be accessible by the
   PostgreSQL user (the user ID the server
   runs as) and the name must be specified from the viewpoint of the
   server. When PROGRAM is specified, the server
   executes the given command and reads from the standard output of the
   program, or writes to the standard input of the program. The command
   must be specified from the viewpoint of the server, and be executable
   by the PostgreSQL user.  When
   STDIN or STDOUT is
   specified, data is transmitted via the connection between the
   client and the server.
  
table_nameThe name (optionally schema-qualified) of an existing table.
column_nameAn optional list of columns to be copied. If no column list is specified, all columns of the table except generated columns will be copied.
queryA SELECT, VALUES, INSERT, UPDATE or DELETE command whose results are to be copied. Note that parentheses are required around the query.
      For INSERT, UPDATE and
      DELETE queries a RETURNING clause
      must be provided, and the target relation must not have a conditional
      rule, nor an ALSO rule, nor an
      INSTEAD rule that expands to multiple statements.
     
filename
      The path name of the input or output file.  An input file name can be
      an absolute or relative path, but an output file name must be an absolute
      path.  Windows users might need to use an E'' string and
      double any backslashes used in the path name.
     
PROGRAM
      A command to execute. In COPY FROM, the input is
      read from standard output of the command, and in COPY TO,
      the output is written to the standard input of the command.
     
Note that the command is invoked by the shell, so if you need to pass any arguments to shell command that come from an untrusted source, you must be careful to strip or escape any special characters that might have a special meaning for the shell. For security reasons, it is best to use a fixed command string, or at least avoid passing any user input in it.
STDINSpecifies that input comes from the client application.
STDOUTSpecifies that output goes to the client application.
boolean
      Specifies whether the selected option should be turned on or off.
      You can write TRUE, ON, or
      1 to enable the option, and FALSE,
      OFF, or 0 to disable it.  The
      boolean value can also
      be omitted, in which case TRUE is assumed.
     
FORMAT
      Selects the data format to be read or written:
      text,
      csv (Comma Separated Values),
      or binary.
      The default is text.
     
FREEZE
      Requests copying the data with rows already frozen, just as they
      would be after running the VACUUM FREEZE command.
      This is intended as a performance option for initial data loading.
      Rows will be frozen only if the table being loaded has been created
      or truncated in the current subtransaction, there are no cursors
      open and there are no older snapshots held by this transaction.  It is
      currently not possible to perform a COPY FREEZE on
      a partitioned table.
     
Note that all other sessions will immediately be able to see the data once it has been successfully loaded. This violates the normal rules of MVCC visibility and users specifying should be aware of the potential problems this might cause.
DELIMITER
      Specifies the character that separates columns within each row
      (line) of the file.  The default is a tab character in text format,
      a comma in CSV format.
      This must be a single one-byte character.
      This option is not allowed when using binary format.
     
NULL
      Specifies the string that represents a null value. The default is
      \N (backslash-N) in text format, and an unquoted empty
      string in CSV format. You might prefer an
      empty string even in text format for cases where you don't want to
      distinguish nulls from empty strings.
      This option is not allowed when using binary format.
     
       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.
      
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 ignored.
      This option is allowed only when using CSV format.
     
QUOTE
      Specifies the quoting character to be used when a data value is quoted.
      The default is double-quote.
      This must be a single one-byte character.
      This option is allowed only when using CSV format.
     
ESCAPE
      Specifies the character that should appear before a
      data character that matches the QUOTE value.
      The default is the same as the QUOTE value (so that
      the quoting character is doubled if it appears in the data).
      This must be a single one-byte character.
      This option is allowed only when using CSV format.
     
FORCE_QUOTE
      Forces quoting to be
      used for all non-NULL values in each specified column.
      NULL output is never quoted. If * is specified,
      non-NULL values will be quoted in all columns.
      This option is allowed only in COPY TO, and only when
      using CSV format.
     
FORCE_NOT_NULL
      Do not match the specified columns' values against the null string.
      In the default case where the null string is empty, this means that
      empty values will be read as zero-length strings rather than nulls,
      even when they are not quoted.
      This option is allowed only in COPY FROM, and only when
      using CSV format.
     
FORCE_NULL
      Match the specified columns' values against the null string, even
      if it has been quoted, and if a match is found set the value to
      NULL. In the default case where the null string is empty,
      this converts a quoted empty string into NULL.
      This option is allowed only in COPY FROM, and only when
      using CSV format.
     
ENCODING
      Specifies that the file is encoded in the encoding_name.  If this option is
      omitted, the current client encoding is used. See the Notes below
      for more details.
     
WHERE
    The optional WHERE clause has the general form
WHERE condition
    where condition is
    any expression that evaluates to a result of type
    boolean.  Any row that does not satisfy this
    condition will not be inserted to the table.  A row satisfies the
    condition if it returns true when the actual row values are
    substituted for any variable references.
   
    Currently, subqueries are not allowed in WHERE
    expressions, and the evaluation does not see any changes made by the
    COPY itself (this matters when the expression
    contains calls to VOLATILE functions).
   
   On successful completion, a COPY command returns a command
   tag of the form
COPY count
   The count is the number
   of rows copied.
  
    psql will print this command tag only if the command
    was not COPY ... TO STDOUT, or the
    equivalent psql meta-command
    \copy ... to stdout.  This is to prevent confusing the
    command tag with the data that was just printed.
   
    COPY TO can be used only with plain
    tables, not views, and does not copy rows from child tables
    or child partitions.  For example, COPY  copies
    the same rows as table TOSELECT * FROM ONLY .
    The syntax tableCOPY (SELECT * FROM  can be used to
    dump all of the rows in an inheritance hierarchy, partitioned table,
    or view.
   table) TO ...
    COPY FROM can be used with plain, foreign, or
    partitioned tables or with views that have
    INSTEAD OF INSERT triggers.
   
    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.
   
    If row-level security is enabled for the table, the relevant
    SELECT policies will apply to COPY
     statements.
    Currently, table TOCOPY FROM is not supported for tables
    with row-level security. Use equivalent INSERT
    statements instead.
   
    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. Similarly,
    the command specified with PROGRAM is executed directly
    by the server, not by the client application, must be executable by the
    PostgreSQL user.
    COPY naming a file or command is only allowed to
    database superusers or users who are granted one of the default roles
    pg_read_server_files,
    pg_write_server_files,
    or pg_execute_server_program, since it allows reading
    or writing any file or running a program 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.
   
    Executing a command with PROGRAM might be restricted
    by the operating system's access control mechanisms, such as SELinux.
   
    COPY FROM will invoke any triggers and check
    constraints on the destination table. However, it will not invoke rules.
   
    For identity columns, the COPY FROM command will always
    write the column values provided in the input data, like
    the INSERT option OVERRIDING SYSTEM
    VALUE.
   
    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 ENCODING
    option or the current client encoding, and output data is encoded
    in ENCODING or the current client encoding, even
    if the data does not pass through the client but is read from or
    written to a file directly by the server.
   
    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.
   
    FORCE_NULL and FORCE_NOT_NULL can be used
    simultaneously on the same column. This results in converting quoted
    null strings to null values and unquoted null strings to empty strings.
   
    When the text format is used,
    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.
   
    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:
   
| Sequence | Represents | 
|---|---|
| \b | Backspace (ASCII 8) | 
| \f | Form feed (ASCII 12) | 
| \n | Newline (ASCII 10) | 
| \r | Carriage return (ASCII 13) | 
| \t | Tab (ASCII 9) | 
| \v | Vertical tab (ASCII 11) | 
| \digits | Backslash followed by one to three octal digits specifies the byte with that numeric code | 
| \xdigits | Backslash xfollowed by one or two hex digits specifies
       the byte 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).
   
All backslash sequences are interpreted after encoding conversion. The bytes specified with the octal and hex-digit backslash sequences must form valid characters in the database encoding.
    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 option 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 rules used by
    PostgreSQL's standard text format, it
    produces and recognizes the common CSV escaping mechanism.
   
    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 columns.
   
    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. You can also use
    FORCE_NULL to convert quoted null string data values to
    NULL.
   
    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.
   
     In CSV format, 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.
    
CSV format 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-format files.
     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 binary format option causes all data to be
    stored/read as binary format rather than as text.  It is
    somewhat faster than the text and CSV formats,
    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.
   
    The binary file format consists
    of a file header, zero or more tuples containing the row data, and
    a file trailer.  Headers and data are in network byte order.
   
PostgreSQL releases before 7.4 used a different binary file format.
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.)
       
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:
If 1, OIDs are included in the data; if 0, not. Oid system columns are not supported in PostgreSQL anymore, but the format still contains the indicator.
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 binary-format 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
distribution).
    
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. Note that oid system columns are not supported in current versions of PostgreSQL.
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:
COPY country TO STDOUT (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';
To copy into a compressed file, you can pipe the output through an external compression program:
COPY country TO PROGRAM 'gzip > /usr1/proj/bray/sql/country_data.gz';
   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 9.0 and is still supported:
COPYtable_name[ (column_name[, ...] ) ] FROM { 'filename' | STDIN } [ [ WITH ] [ BINARY ] [ DELIMITER [ AS ] 'delimiter_character' ] [ NULL [ AS ] 'null_string' ] [ CSV [ HEADER ] [ QUOTE [ AS ] 'quote_character' ] [ ESCAPE [ AS ] 'escape_character' ] [ FORCE NOT NULLcolumn_name[, ...] ] ] ] COPY {table_name[ (column_name[, ...] ) ] | (query) } TO { 'filename' | STDOUT } [ [ WITH ] [ BINARY ] [ DELIMITER [ AS ] 'delimiter_character' ] [ NULL [ AS ] 'null_string' ] [ CSV [ HEADER ] [ QUOTE [ AS ] 'quote_character' ] [ ESCAPE [ AS ] 'escape_character' ] [ FORCE QUOTE {column_name[, ...] | * } ] ] ]
   Note that in this syntax, BINARY and CSV are
   treated as independent keywords, not as arguments of a FORMAT
   option.
  
The following syntax was used before PostgreSQL version 7.3 and is still supported:
COPY [ BINARY ]table_nameFROM { 'filename' | STDIN } [ [USING] DELIMITERS 'delimiter_character' ] [ WITH NULL AS 'null_string' ] COPY [ BINARY ]table_nameTO { 'filename' | STDOUT } [ [USING] DELIMITERS 'delimiter_character' ] [ WITH NULL AS 'null_string' ]