1: /*
   2: **	Structures Used In The Nodes Of The Querytree
   3: */
   4: 
   5: /*
   6: **	Basic symbol structure. "Type" is one of the symbols
   7: **	in "symbol.h", "len" is the length of the "value"
   8: **	field (0 to 255 bytes), "value" is variable length and
   9: **	holds the actual value (if len != 0) of the node.
  10: */
  11: struct symbol
  12: {
  13:     char    type;           /* type codes in symbol.h */
  14:     char    len;            /* length in bytes of value field */
  15:     int value[];        /* variable length (0 - 255 bytes) */
  16: };
  17: 
  18: /*
  19: **	Basic node in the querytree. Each node has a left and
  20: **	right descendent. If the node is a leaf node then the
  21: **	left and right pointers will be NULL. Depending on the
  22: **	"type" field of the symbol structure, there may be additional
  23: **	information. The cases are itemized below.
  24: */
  25: 
  26: struct querytree
  27: {
  28:     struct querytree    *left;
  29:     struct querytree    *right;
  30:     struct symbol       sym;
  31: };
  32: 
  33: 
  34: /*
  35: **	Variable nodes of the form:
  36: **		varno.attno
  37: **	"Varno" is the variable number which can be translated
  38: **	to a relation name by indexing into the range table.
  39: **	"Attno" is the attribute number specifically the
  40: **	"attid" field in the attribute tuple for the attribute.
  41: **	"Frmt" and "frml" are the type and length of the attribute.
  42: **	"Valptr" is used only in decomposition. If the variable
  43: **	is tuple substituted then "valptr" will have a pointer to
  44: **	the substituted value for the attribute; otherwise it will
  45: **	be NULL. If reduction or one variable restriction has changed
  46: **	the attribute number, then "valptr" will point to the next
  47: **	active VAR node for this VAR.
  48: */
  49: 
  50: struct qt_var
  51: {
  52:     char    filler[6];
  53:     char    varno;
  54:     char    attno;
  55:     char    frmt;
  56:     char    frml;
  57:     char    *valptr;
  58: };
  59: 
  60: 
  61: /*
  62: **	Structure for ROOT, AGHEAD, and AND nodes. In the parser and qrymod
  63: **	these nodes are of length zero and none of this information
  64: **	is present. Decomp maintains information about the variables
  65: **	in the left and right descendents of the nodes.
  66: **	The "rootuser" flag is present only in the ROOT and AGHEAD nodes.
  67: **	It is TRUE only in the original ROOT node of the query.
  68: */
  69: 
  70: struct qt_root
  71: {
  72:     char    filler[6];
  73:     char    tvarc;      /* total of var's in sub-tree */
  74:     char    lvarc;      /* # of variables in left branch */
  75:     int lvarm;      /* bit map of var's in left branch */
  76:     int rvarm;      /* bit map of var's in right branch*/
  77:     int rootuser;   /* flag: TRUE if root of user generated query */
  78: };
  79: 
  80: struct qt_res                   /* RESDOM and AOP nodes */
  81: {
  82:     char    filler[6];
  83:     int resno;          /* result domain number */
  84:                     /* type and length are referenced as
  85: 					** frmt and frml */
  86: };
  87: 
  88: struct qt_ag
  89: {
  90:     char    filler[6];
  91:     char    filler2[4];     /* fill in over aop_type, frmt, and frml */
  92:     char    agfrmt, agfrml;     /* result format type and length for agg's */
  93: };
  94: struct qt_op
  95: {
  96:     char    filler[6];
  97:     int opno;           /* operator number */
  98: };
  99: 
 100: struct qt_v
 101: {
 102:     int fill[2];
 103:     char    vtype;  /* variable type */
 104:     char    vlen;   /* variable length */
 105:     int *vpoint;    /* variable pointer to value */
 106: };
 107: /*
 108: ** structure for referencing a SOURCEID type symbol for
 109: **	pipe transmission
 110: **
 111: **	SOURCEID is a range table element.
 112: */
 113: struct srcid
 114: {
 115:     char    type;           /* type codes in symbol.h */
 116:     char    len;            /* length in bytes of value field */
 117:     int srcvar;         /* variable number */
 118:     char    srcname[MAXNAME];   /* relation name */
 119:     char    srcown[2];      /* relation owner usercode */
 120:     int srcstat;        /* relstat field */
 121: };

Defined struct's

qt_var defined in line 50; used 292 times
querytree defined in line 26; used 642 times
symbol defined in line 11; used 188 times

Usage of this include

tree.h used 79 times
Last modified: 1995-02-19
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