This is an original mandamus proceeding. Relators are indicted criminal defendants who petition this court to mandate the circuit judge and district attorney to conduct a preliminary hearing or dismiss the charges. Relators claim entitlement to a preliminary hearing, notwithstanding their indictment. The defendants on the writ assert, among other things, that mandamus is not a proper remedy because the relators may appeal if convicted.
The power of this court to issue writs of mandamus is granted by the constitution, Or Const, Art VII (Am), § 2,1 and defined by statute, ORS 34.110, which embodies conventional mandamus theory. It states:
"* * * The writ shall not be issued in any case where there is a plain, speedy and adequate remedy in the ordinary coruse of the law.”
As relators acknowledge, direct appeal in criminal cases is generally regarded as a "plain, speedy and adequate remedy in the ordinary course of the law,” State ex rel Maizels v. Juba, 254 Or 323, 331-34, 460 P2d 850 (1969); Henkel v. Bradshaw, 257 Or 55, 475 P2d 75 (1970). A denial of a preliminary hearing is a ruling which may be reviewed on direct appeal. ORS 138.020 and 138.040,2 State v. Sanford, *268245 Or 397, 405, 421 P2d 988 (1966), State v. Walley, 1 Or App 189, 460 P2d 370 (1969); cf. State v. Pfeiffer, 25 Or App 45, 548 P2d 174 (1976); see also Anderson v. Gladden, 234 Or 614, 627, 383 P2d 986 (1963). Therefore, in the absence of special circumstances, relators have a plain, speedy and adequate remedy in the form of a direct appeal.
The relators contend that direct appeal is not an adequate remedy because they will be prejudiced in two respects if forced to trial without a preliminary hearing: they will be denied (1) pretrial discovery of the testimony of a prosecution witness who has refused to be interviewed, and (2) a pretrial opportunity to determine whether the state has probable cause to require them to answer to the charge.3 The issue is whether this constitutes such prejudice as renders direct appeal a less than adequate remedy. We conclude that it is not.
As to the first contention, there is no difference relevant to mandamus between this and any other pretrial ruling denying discovery. Any claim of prejudice arising from a denial of discovery is reviewable on direct appeal. State v. Wolfe, 273 Or 518, 542 P2d 482 (1975); State v. King, 30 Or App 223, 566 P2d 1204 (1977); State v. Castro, 25 Or App 873, 551 P2d 488 (1976).4 This is to be distinguished from a discovery order which erroneously requires disclosure of *269privileged communications, State ex rel N. Pacific Lbr. v. Unis, 282 Or 457, 579 P2d 1291 (1978), or which requires disclosure by a party (e.g., the state) which has no post-trial appeal from an adverse judgment, State ex rel Johnson v. Richardson, 276 Or 325, 555 P2d 202 (1976). Those cases are distinguishable in that relators suffered an irretrievable loss of information and tactical advantage which could not be restored to them on direct appeal. Relators here are not prejudiced by the requirement that they defer review of their claim of denial of discovery until direct appeal. Were their assertion correct, every pretrial discovery ruling would be subject to review by mandamus.
Neither is the prospect of suffering the burden of litigation a sufficient injury in itself to justify mandamus. Direct appeal is an adequate remedy unless the relator would suffer a special loss beyond the burden of litigation by being forced to trial.5 Examples of such injury are the obligation to make nonrecoverable interim payments of compensation, State ex rel Huntington v. Sulmonetti, 276 Or 967, 557 P2d 641 (1976), and being required to relitigate when a summary judgment is set aside by the trial court after its authority to do so has expired, State ex rel State Farm Mutual Auto Ins. Co. v. Olsen, 285 Or 179, 590 P2d 231 (1979). Here, however, there is no special loss asserted.
Because direct appeal is a plain, speedy and adequate remedy for the review of the ruling challenged by relators, mandamus is inappropriate. The writ is therefore dismissed.
Alternative writ of mandamus dismissed.
Or Const, Art VII (Am), § 2:
"The courts, jurisdiction, and judicial system of Oregon, except so far as expressly changed by this amendment, shall remain as at present constituted until otherwise provided by law. But the supreme court may, in its own discretion, take original jurisdiction in mandamus, quo warranto and habeas corpus proceedings.
ORS 138.020 states:
"Either the state or the defendant may as a matter of right appeal from a judgment in a criminal action in the cases prescribed in [ORS 138.040] and not otherwise.”
ORS 138.040 states:
"The defendant may appeal to the Court of Appeals from a judgment on a conviction in a district or circuit court * * *. Upon appeal * * * any decision of the court in an intermediate order or proceeding may be reviewed. * * *”
Because relators do not allege that they are being detained, the second allegation of prejudice means only that they will be forced to litigate.
The dissent asserts that we should reach the issue urged by relators because, if convicted, it will be difficult for them on direct appeal to demonstrate prejudice. That may be. Regarding relators’ claim of entitlement to a probable cause determination, it is true after a verdict beyond reasonable doubt that relators will be hard put to claim prejudice arising from a denial of a pretrial probable cause hearing. Regarding relators’ right to discovery, the existence or not of prejudice will be an issue as in any appellate review of a denial of discovery, State v. Wolfe, supra. Such an appeal might differ from Wolfe, however, in that if federal constitutional error is found, we must reverse unless we can declare it harmless beyond a reasonable doubt. State v. McLean, 255 Or 464, 477-79, 468 P2d 521 (1970).
An exception exists where the relator asserts that a court is improperly asserting jurisdiction, State ex rel Knapp v. Sloper, 256 Or 299, 473 P2d 140 (1970), State ex rel Handly v. Hieber, 256 Or 93, 471 P2d 790 (1970). This exception has also been extended to cases of improper venue. Mack Trucks, Inc. v. Taylor, 227 Or 376, 382, 362 P2d 364 (1961) (dicta); State ex rel Ricco v. Biggs, 198 Or 413, 425, 255 P2d 1055 (1953); Willamette Lbr. Co. v. Cir. Ct., Mult. Co., 187 Or 591, 598, 211 P2d 994 (1949). Neither jurisdiction nor venue is in issue here.